Document and Entity Information	12 Months Ended
Document and Entity Information	Dec. 31, 2018 shares
Entity Registrant Name	Niu Technologies
Entity Central Index Key	0001744781
Document Type	20-F
Document Period End Date	Dec. 31, 2018
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	FY
Class A Ordinary Shares
Entity Common Stock, Shares Outstanding	128,032,038
Class B Ordinary Shares
Entity Common Stock, Shares Outstanding	20,642,020

CONSOLIDATED BALANCE SHEETS	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)
Current assets
Cash	$ 82,766,285	¥ 569,059,591	¥ 111,996,325
Term deposit	3,992,824	27,452,663
Restricted cash-current	26,072,680	179,262,714	104,547,200
Short-term investments	17,488,390	120,241,425	85,187,718
Accounts receivable, net	7,915,765	54,424,845	10,382,112
Inventories	20,708,633	142,382,205	88,225,965
Prepayments and other current assets	3,915,345	26,919,954	7,349,583
Total current assets	162,859,922	1,119,743,397	407,688,903
Non-current assets
Restricted cash-non current			65,342,000
Property and equipment, net	5,961,046	40,985,174	28,696,602
Intangible asset, net	1,122,501	7,717,754	1,277,467
Other non-current assets	2,444,256	16,805,474	626,605
Total non-current assets	9,527,803	65,508,402	95,942,674
Total assets	172,387,725	1,185,251,799	503,631,577
Current liabilities
Short-term bank borrowings (including short-term bank borrowings of VIE without recourse to the Company of RMB168,234,207 and RMB179,978,003 as of December 31, 2017 and 2018, respectively)	26,176,715	179,978,003	168,234,207
Convertible loan			151,557,796
Accounts payable (including accounts payable of VIE without recourse to the Company of RMB124,937,465 and RMB249,665,890 as of December 31, 2017 and 2018, respectively)	36,312,398	249,665,890	124,937,465
Advances from customers (including advances from customers of VIE without recourse to the Company of RMB48,503,389 and RMB20,505,861 as of December 31, 2017 and 2018, respectively)	2,982,454	20,505,861	48,503,389
Deferred revenue - current (including deferred revenue-current of VIE without recourse to the Company of RMB9,853,361 and RMB12,666,330 as of December 31, 2017 and 2018, respectively)	1,842,241	12,666,330	9,853,361
Accrued expenses and other current liabilities (including accrued expenses and other current liabilities of VIE without recourse to the Company of RMB75,382,869 and RMB119,242,975 as of December 31, 2017 and 2018, respectively)	19,516,258	134,184,026	75,412,869
Total current liabilities	86,830,066	597,000,110	578,499,087
Non-current liabilities
Warranty-non current (including warranty-non current of VIE without recourse to the Company of RMB12,378,751 and RMB17,609,842 as of December 31, 2017 and 2018, respectively)	2,561,245	17,609,842	12,378,751
Deferred revenue - non current (including deferred revenue-non current of VIE without recourse to the Company of RMB144,700 and RMB234,801 as of December 31, 2017 and 2018, respectively)	34,150	234,801	144,700
Total non-current liabilities	2,595,395	17,844,643	12,523,451
Total liabilities	89,425,461	614,844,753	591,022,538
MEZZANINE EQUITY
Total mezzanine equity			237,844,515
SHAREHOLDERS' (DEFICIT) / EQUITY:
Ordinary Shares			39,948
Additional paid-in capital	249,797,622	1,717,483,548	440,265,896
Accumulated other comprehensive income/(loss)	(3,314,220)	(22,786,922)	5,596,238
Accumulated deficit	(163,535,094)	(1,124,385,539)	(771,155,994)
Total shareholders' (deficit)/equity	82,962,264	570,407,046	(325,235,476)
Total liabilities, mezzanine equity and shareholders' (deficit)/equity	172,387,725	1,185,251,799	503,631,577
Series A1 Redeemable Convertible Preferred Shares
MEZZANINE EQUITY
Total mezzanine equity			130,684,003
Series A-2 Redeemable Convertible Preferred Shares
MEZZANINE EQUITY
Total mezzanine equity			39,205,192
Series A-3 Redeemable Convertible Preferred Shares
MEZZANINE EQUITY
Total mezzanine equity			67,955,320
Class A Ordinary Shares
SHAREHOLDERS' (DEFICIT) / EQUITY:
Ordinary Shares	12,089	83,120
Class B Ordinary Shares
SHAREHOLDERS' (DEFICIT) / EQUITY:
Ordinary Shares	$ 1,867	¥ 12,839
Series Seed Convertible Preferred Shares
SHAREHOLDERS' (DEFICIT) / EQUITY:
Series Seed Convertible Preferred Shares (US$0.0001 par value, 30,000,000 and nil shares authorized, issued and outstanding as of December 31, 2017 and 2018)			¥ 18,436

CONSOLIDATED BALANCE SHEETS (Parenthetical)	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2018 CNY (¥) shares	Dec. 31, 2017 CNY (¥) shares
Short-term bank borrowings	$ 26,176,715	¥ 179,978,003	¥ 168,234,207
Accounts payable	36,312,398	249,665,890	124,937,465
Advances from customers	2,982,454	20,505,861	48,503,389
Deferred revenue - current	1,842,241	12,666,330	9,853,361
Accrued expenses and other current liabilities	19,516,258	134,184,026	75,412,869
Warranty - non current	2,561,245	17,609,842	12,378,751
Deferred revenue - non current	$ 34,150	¥ 234,801	¥ 144,700
Ordinary shares, authorized			444,721,650
Ordinary shares, issued			64,570,520
Ordinary shares, outstanding			64,570,520
Series A1 Redeemable Convertible Preferred Shares
Redeemable Convertible Preferred Shares, par value (in dollars per share) \| $ / shares	$ 0.0001
Redeemable Convertible Preferred Shares, authorized	0	0	16,666,667
Redeemable Convertible Preferred Shares, issued	0	0	16,666,667
Redeemable Convertible Preferred Shares, outstanding	0	0	16,666,667
Redemption value \| ¥		¥ 0	¥ 130,684,003
Liquidation value \| ¥		¥ 0	¥ 196,026,005
Series A-2 Redeemable Convertible Preferred Shares
Redeemable Convertible Preferred Shares, par value (in dollars per share) \| $ / shares	$ 0.0001
Redeemable Convertible Preferred Shares, authorized	0	0	3,608,247
Redeemable Convertible Preferred Shares, issued	0	0	3,608,247
Redeemable Convertible Preferred Shares, outstanding	0	0	3,608,247
Redemption value \| ¥		¥ 0	¥ 39,205,192
Liquidation value \| ¥		¥ 0	¥ 58,807,788
Series A-3 Redeemable Convertible Preferred Shares
Redeemable Convertible Preferred Shares, par value (in dollars per share) \| $ / shares	$ 0.0001
Redeemable Convertible Preferred Shares, authorized	0	0	5,003,436
Redeemable Convertible Preferred Shares, issued	0	0	5,003,436
Redeemable Convertible Preferred Shares, outstanding	0	0	5,003,436
Redemption value \| ¥		¥ 0	¥ 67,955,320
Liquidation value \| ¥		¥ 0	¥ 101,932,980
Class A Ordinary Shares
Ordinary shares, par value (in dollars per share) \| $ / shares	$ 0.0001
Ordinary shares, authorized	4,900,000,000	4,900,000,000
Ordinary shares, issued	128,032,038	128,032,038
Ordinary shares, outstanding	128,032,038	128,032,038
Class B Ordinary Shares
Ordinary shares, par value (in dollars per share) \| $ / shares	$ 0.0001
Ordinary shares, authorized	50,000,000	50,000,000
Ordinary shares, issued	20,642,020	20,642,020
Ordinary shares, outstanding	20,642,020	20,642,020
Series Seed Convertible Preferred Shares
Series Seed Convertible Preferred Shares, par value (in dollars per share) \| $ / shares	$ 0.0001
Series Seed Convertible Preferred Shares, authorized	0	0	30,000,000
Series Seed Convertible Preferred Shares, issued	0	0	30,000,000
Series Seed Convertible Preferred Shares, outstanding	0	0	30,000,000
VIE
Short-term bank borrowings \| ¥		¥ 179,978,003	¥ 168,234,207
Accounts payable \| ¥		249,665,890	124,937,465
Advances from customers \| ¥		20,505,861	48,503,389
Deferred revenue - current \| ¥		12,666,330	9,853,361
Accrued expenses and other current liabilities \| ¥		119,242,975	75,382,869
Warranty - non current \| ¥		17,609,842	12,378,751
Deferred revenue - non current \| ¥		¥ 234,801	¥ 144,700

CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS	12 Months Ended
CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2018 CNY (¥) ¥ / shares shares	Dec. 31, 2017 CNY (¥) ¥ / shares shares	Dec. 31, 2016 CNY (¥) ¥ / shares shares
CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS
Net revenues	$ 214,934,376	¥ 1,477,781,304	¥ 769,368,001	¥ 354,810,048
Cost of revenues	(186,045,502)	(1,279,155,847)	(714,669,718)	(367,587,499)
Gross (loss)/profit	28,888,874	198,625,457	54,698,283	(12,777,451)
Operating expenses:
Selling and marketing expenses	(21,838,539)	(150,150,872)	(83,064,894)	(89,753,835)
Research and development expenses	(13,353,486)	(91,811,892)	(39,492,743)	(33,089,565)
General and administrative expenses	(39,867,741)	(274,110,654)	(76,411,871)	(90,839,388)
Operating loss	(46,170,892)	(317,447,961)	(144,271,225)	(226,460,239)
Change in fair value of a convertible loan	(5,017,796)	(34,499,858)	(43,006,399)
Interest expenses	(1,123,071)	(7,721,675)	(3,153,521)	(2,320,169)
Interest income	436,157	2,998,796	1,006,972	660,601
Investment income	669,311	4,601,849	2,315,536	370,118
Foreign currency exchange (losses)/gain	239,426	1,646,173	1,612,766	(6,279,783)
Government grants	202,923	1,395,200	833,000	1,308,550
Loss before income taxes	(50,763,942)	(349,027,476)	(184,662,871)	(232,720,922)
Net loss	(50,763,942)	(349,027,476)	(184,662,871)	(232,720,922)
Other comprehensive (losses)/income:
Foreign currency translation adjustment, net of nil income taxes	(4,135,971)	(28,436,867)	9,994,461	(2,674,062)
Unrealized gain on available for sale securities, net of nil income taxes	677,123	4,655,556	2,415,901	457,471
Less: reclassification adjustment for gain on available for sale securities realized in net income, net of nil income taxes	(669,311)	(4,601,849)	(2,315,536)	(370,118)
Comprehensive loss	$ (54,892,101)	¥ (377,410,636)	¥ (174,568,045)	¥ (235,307,631)
Net loss per ordinary share
Basic and diluted \| (per share)	$ (0.77)	¥ (5.30)	¥ (7.02)	¥ (22.35)
Weighted average number of shares outstanding used in computing net loss per ordinary share
Basic and diluted	65,834,876	65,834,876	26,295,181	10,414,325

CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Parenthetical) - CNY (¥)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS
Foreign currency translation adjustment, income tax	¥ 0	¥ 0	¥ 0
Unrealized gain on available for sale securities, income tax	0	0	0
Reclassification adjustment for gain on available for sale securities realized in net income, income tax	¥ 0	¥ 0	¥ 0

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' (DEFICIT) / EQUITY	Ordinary shares Series Seed Convertible Preferred Shares CNY (¥) shares	Ordinary shares Class A Ordinary Shares CNY (¥) shares	Ordinary shares Class B Ordinary Shares CNY (¥) shares	Ordinary shares USD ($) shares	Ordinary shares CNY (¥) shares	Series Seed Convertible Preferred Shares Series Seed Convertible Preferred Shares CNY (¥) shares	Series Seed Convertible Preferred Shares CNY (¥) shares	Additional paid-in capital Class A Ordinary Shares CNY (¥)	Additional paid-in capital Class B Ordinary Shares CNY (¥)	Additional paid-in capital USD ($)	Additional paid-in capital CNY (¥)	Accumulated other comprehensive (loss) / income USD ($)	Accumulated other comprehensive (loss) / income CNY (¥)	Accumulated deficit USD ($)	Accumulated deficit CNY (¥)	Class A Ordinary Shares CNY (¥)	Class B Ordinary Shares CNY (¥)	USD ($)	CNY (¥)
Beginning balance at Dec. 31, 2015					¥ 36,593		¥ 18,436				¥ 299,433,895		¥ (1,911,879)		¥ (353,772,201)				¥ (56,195,156)
Beginning balance (in shares) at Dec. 31, 2015 \| shares				59,459,020	59,459,020		30,000,000
Increase (decrease) in shareholders' deficit
Issuance of ordinary shares					¥ 3,355														3,355
Issuance of ordinary shares (in shares) \| shares				5,111,500	5,111,500
Share-based compensation											78,304,903								78,304,903
Net loss															(232,720,922)				(232,720,922)
Foreign currency translation adjustment, net of nil income taxes													(2,674,062)						(2,674,062)
Unrealized holding gains on available-for-sale security, net of nil income taxes													457,471						457,471
Reclassification adjustment for gain on available for sale securities realized in net income, net of nil income taxes													(370,118)						(370,118)
Ending balance at Dec. 31, 2016					¥ 39,948		¥ 18,436				377,738,798		(4,498,588)		(586,493,123)				(213,194,529)
Ending balance (in shares) at Dec. 31, 2016 \| shares				64,570,520	64,570,520		30,000,000
Increase (decrease) in shareholders' deficit
Share-based compensation											62,527,098								62,527,098
Net loss															(184,662,871)				(184,662,871)
Foreign currency translation adjustment, net of nil income taxes													9,994,461						9,994,461
Unrealized holding gains on available-for-sale security, net of nil income taxes													2,415,901						2,415,901
Reclassification adjustment for gain on available for sale securities realized in net income, net of nil income taxes													(2,315,536)						(2,315,536)
Ending balance at Dec. 31, 2017					¥ 39,948		¥ 18,436				440,265,896		5,596,238		(771,155,994)				(325,235,476)
Ending balance (in shares) at Dec. 31, 2017 \| shares				64,570,520	64,570,520		30,000,000
Increase (decrease) in shareholders' deficit
Issuance of ordinary shares					¥ 9,714						383,308,578								383,318,292
Issuance of ordinary shares (in shares) \| shares				14,000,000	14,000,000
Share-based compensation											265,874,927								265,874,927
Repurchase and retirement of ordinary shares					¥ (266)										(4,202,069)				(4,202,335)
Repurchase and retirement of ordinary shares (in shares) \| shares				(432,000)	(432,000)
Conversion of preferred shares into ordinary shares	¥ 18,436	¥ 24,562	¥ 3,565			¥ (18,436)		¥ 451,100,862	¥ 176,933,285							¥ 451,125,424	¥ 176,936,850		628,062,274
Conversion of preferred shares into ordinary shares (in shares) \| shares	30,000,000	35,397,679	5,137,859			(30,000,000)
Net loss															(349,027,476)			$ (50,763,942)	(349,027,476)
Foreign currency translation adjustment, net of nil income taxes													(28,436,867)					(4,135,971)	(28,436,867)
Unrealized holding gains on available-for-sale security, net of nil income taxes													4,655,556					677,123	4,655,556
Reclassification adjustment for gain on available for sale securities realized in net income, net of nil income taxes													(4,601,849)					(669,311)	(4,601,849)
Ending balance at Dec. 31, 2018				$ 13,956	¥ 95,959					$ 249,797,622	¥ 1,717,483,548	$ (3,314,220)	¥ (22,786,922)	$ (163,535,094)	¥ (1,124,385,539)			$ 82,962,264	¥ 570,407,046
Ending balance (in shares) at Dec. 31, 2018 \| shares				148,674,058	148,674,058

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' (DEFICIT) / EQUITY (Parenthetical) - CNY (¥)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' (DEFICIT) / EQUITY
Foreign currency translation adjustment, income tax	¥ 0	¥ 0	¥ 0
Unrealized holding gains on available-for-sale security, income tax	0	0	0
Reclassification adjustment for gains on available-for-sale securities realized in net income, income tax	¥ 0	¥ 0	¥ 0

CONSOLIDATED STATEMENTS OF CASH FLOWS	12 Months Ended
CONSOLIDATED STATEMENTS OF CASH FLOWS	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
Operating activities:
Net loss	$ (50,763,942)	¥ (349,027,476)	¥ (184,662,871)	¥ (232,720,922)
Adjustments to reconcile net loss to net cash (used in)/provided by operating activities
Allowance (reversals) for doubtful accounts	(176,782)	(1,215,464)	1,908,399	47,846
Share-based compensation	38,669,904	265,874,927	62,527,098	78,304,903
Change in fair value of a convertible loan	5,017,796	34,499,858	43,006,399
Depreciation and amortization	2,746,182	18,881,376	9,746,569	5,187,772
Investment income	(669,311)	(4,601,849)	(2,315,536)	(370,118)
Unrealized foreign exchange loss	15,785	108,528	219,885	4,445,782
Loss on disposal of property and equipment	33,121	227,720	4,697
Write-down of inventory	2,654,993	18,254,406	0	0
Interest income from restricted cash	(114,865)	(789,751)
Changes in operating assets and liabilities:
Accounts receivable	(6,228,968)	(42,827,269)	8,307,152	(19,215,134)
Inventories	(10,531,692)	(72,410,646)	(21,444,209)	(37,322,088)
Prepayments and other current assets	(2,846,392)	(19,570,371)	24,498,743	(10,954,173)
Other non-current assets	(18,937)	(130,199)
Accounts payable	18,140,997	124,728,425	53,119,693	48,615,385
Advances from customers	(4,072,072)	(27,997,528)	35,169,999	5,648,819
Deferred revenue	422,234	2,903,070	5,143,914	4,854,147
Warranty-non current	760,831	5,231,091	5,682,222	3,518,056
Accrued expenses and other current liabilities	8,092,578	55,640,518	39,151,124	26,905,991
Net cash (used in)/provided by operating activities	1,131,460	7,779,366	80,063,278	(123,053,734)
Investing activities:
Cash paid for purchase of property and equipment	(4,656,808)	(32,017,882)	(23,244,485)	(10,320,052)
Prepayments for land use rights	(1,793,274)	(12,329,652)
Purchase of intangible assets	(1,300,544)	(8,941,893)
Purchase of term deposits	(13,895,844)	(95,540,873)
Cash received from redemption of term deposits	11,001,207	75,638,800
Cash paid for purchase of short-term investments	(190,240,710)	(1,308,000,000)	(412,000,000)	(110,000,000)
Cash received from sale of short-term investments	185,819,482	1,277,601,849	379,315,536	60,370,118
Net cash used in investing activities	(15,066,491)	(103,589,651)	(55,928,949)	(59,949,934)
Financing activities:
Proceeds from issuance of Class A Ordinary Shares upon IPO, net of underwriting commissions and discounts of RMB30,599,667	59,128,563	406,538,433
Payment of issuance cost of Class A Ordinary Shares in connection with IPO	(2,921,897)	(20,089,502)
Cash paid for repurchase of Ordinary Shares	(611,204)	(4,202,335)
Issuance of Restricted Ordinary Shares				3,355
Restricted cash paid as collateral for short-term bank borrowings			(66,288,600)	(64,713,277)
Proceeds from a convertible loan				115,808,672
Proceeds from short-term bank borrowings	29,085,594	199,978,003	118,701,147	112,795,310
Repayment for short-term bank borrowings	(27,377,530)	(188,234,207)	(49,997,837)	(49,834,330)
Net cash provided by financing activities	80,777,047	555,382,588	2,414,710	225,011,777
Effect of foreign currency exchange rate changes on cash	(364,921)	(2,509,037)	(5,673,424)	2,061,790
Net increase in cash	66,477,095	457,063,266	20,875,615	44,069,899
Cash at the beginning of the year	16,289,190	111,996,325	91,120,710	47,050,811
Cash at the end of the year	82,766,285	569,059,591	111,996,325	91,120,710
Supplemental information
Interest paid	1,113,620	7,656,695	3,117,410	2,189,011
Payable for issuance cost of Class A Ordinary Shares in connection with IPO	(455,333)	(3,130,639)
Series A1 Redeemable Convertible Preferred Shares
Financing activities:
Proceeds from issuance of Redeemable Convertible Preferred Shares			¥ 43,068,820	43,068,820
Series A-3 Redeemable Convertible Preferred Shares
Financing activities:
Proceeds from issuance of Redeemable Convertible Preferred Shares				¥ 67,883,227
Series B Redeemable Convertible Preferred Shares
Financing activities:
Proceeds from issuance of Redeemable Convertible Preferred Shares	$ 23,473,521	¥ 161,392,196

DESCRIPTION OF ORGANIZATION AND PRINCIPAL ACTIVITIES

12 Months Ended

Dec. 31, 2018

DESCRIPTION OF ORGANIZATION AND PRINCIPAL ACTIVITIES

DESCRIPTION OF ORGANIZATION AND PRINCIPAL ACTIVITIES

1. DESCRIPTION OF ORGINAZATION AND PRINCIPAL ACTIVITIES

Organization and principal activities

Niu Technologies ("the Company"), through its wholly-owned subsidiaries, consolidated variable interest entity ("VIE") and VIE’s subsidiaries (collectively referred to as "the Group"), is principally engaged in designing, manufacturing and selling of smart electric-scooters and its accessories under the brand name of "NIU". The Group’s principal operations and geographic markets are mainly in the People’s Republic of China ("PRC").

The accompanying consolidated financial statements include the financial statements of the Company, its wholly-owned subsidiaries, consolidated VIE and VIE’s subsidiaries.

The VIE arrangements

The Group operates its online business in the PRC through Beijing Niudian Technologies Co., Ltd. ("Beijing Niudian", or the "VIE"), a limited liability company established under the laws of the PRC on September 18, 2014. Beijing Niudian holds the necessary PRC operating licenses for the online business. The equity interests of Beijing Niudian are legally held by individuals who act as nominee equity holders of the VIE on behalf of Beijing Niudian Information Technology Co., Ltd. ("Niudian Information"), the Company’s wholly owned subsidiary. A series of contractual agreements, including Powers of Attorney, Exclusive Business Cooperation Agreement, Equity Pledge Agreement, Exclusive Option Agreement and Spousal Consent Letters (collectively, the "VIE Agreements"), were entered among the Company, Niudian Information, Beijing Niudian and its nominee equity holders on May 27, 2015 and were subsequently amended to include registration of the Equity Pledge Agreement with the relevant registration authority on June 11, 2018 and amended when an equity holder transferred certain equity interests to another equity holder on July 20, 2018.

Pursuant to the VIE Agreements, the Company is able to exercise effective control over, bears the risks of, enjoys substantially all of the economic benefits of the VIE, and has an exclusive option to purchase all or part of the equity interests in the VIE when and to the extent permitted by PRC law at the lowest price possible. The Company’s management concluded that Beijing Niudian is a VIE and the Company is its primary beneficiary. As such, the consolidated financial statements of the VIE are included in the consolidated financial statements of the Company.

The principal terms of the VIE Agreements are further described below.

1) Powers of Attorney

The Company and each of the equity holders of Beijing Niudian entered into Powers of Attorney. Pursuant to the Powers of Attorney, the equity holders of Beijing Niudian irrevocably appointed the Company as their attorney-in-fact to exercise all equity holder rights, including, but not limited to, convening and attending in the equity holders’ meeting, appointing or removing directors, executive officers and senior management, disposing of all or part of the equity holder’s interests in Beijing Niudian, casting equity holder’s vote on matters requiring equity holders’ approval and doing all other acts in the capacity of equity holder as permitted by Beijing Niudian’s Memorandum and Articles of Association. In addition, the Company has a right to assign its rights and benefits under the Powers of Attorney to any other parties without an advance notice to the equity holders of Beijing Niudian. The Powers of Attorney shall continue in force and be irrevocable as long as the equity holders of Beijing Niudian remain as the equity holders of Beijing Niudian.

2) Exclusive Business Cooperation Agreement

Niudian Information and Beijing Niudian entered into an Exclusive Business Cooperation Agreement, whereby Niudian Information is appointed as the exclusive service provider for the provision of business support, technology and consulting services to Beijing Niudian. Unless a written consent is given by Niudian Information, Beijing Niudian is not allowed to engage a third party to provide such services, while Niudian Information is able to designate another party to render such services to Beijing Niudian. Beijing Niudian shall pay Niudian Information on a monthly basis a service fee, which shall equal to 100% of the monthly net profits of Beijing Niudian, and Niudian Information has the sole discretion to adjust the basis of calculation of the service fee amount according to service provided to Beijing Niudian. Niudian Information owns the exclusive intellectual property rights, whether created by Niudian Information or Beijing Niudian, as a result of the performance of the Exclusive Business Cooperation Agreement unless terminated in writing by Niudian Information. The Exclusive Business Cooperation Agreement will be in effect until September 17, 2044 which represents the end of operation term of Beijing Niudian.

3) Equity Pledge Agreement

An Equity Pledge Agreement was entered into by and among Niudian Information, Beijing Niudian and equity holders of Beijing Niudian. To guarantee payment from Beijing Niudian, including but not limited to the service fee pursuant to the Exclusive Business Cooperation Agreement, and the performance of Beijing Niudian and the nominee equity holders’ obligations under the contractual arrangements including the Exclusive Business Cooperation Agreement, Exclusive Option Agreement and Powers of Attorney, the equity holders of Beijing Niudian pledged their respective equity in Niudian Information under the Equity Pledge Agreement to Niudian Information as collateral. In the event Beijing Niudian fails to pay Niudian Information its service fee, Niudian Information will have the right to sell the pledged equity and apply the proceeds received to pay any outstanding service fees due by Beijing Niudian to Niudian Information. The equity holders of Beijing Niudian agree that, during the term of the Equity Pledge Agreement, they will not dispose of the pledged equity or create or allow any encumbrance on the pledged equity, and they also agree that Niudian Information’s rights relating to the equity pledges shall not be prejudiced by any legal actions of the equity holders of Beijing Niudian, their successors or their designees. The equity pledges have been registered with the relevant registration authority and became effective and enforceable since registration. The Equity Pledge Agreement may only be terminated upon the fulfillment of all contractual obligations under the Exclusive Business Cooperation Agreement, Exclusive Option Agreement and Powers of Attorney. During the term of the Equity Pledge Agreement, Niudian Information is entitled to receive dividends attributable to the pledged Beijing Niudian equity.

4) Exclusive Option Agreement

Each of the equity holders of Beijing Niudian entered into an Exclusive Option Agreement with the Company, Niudian Information, and Beijing Niudian, pursuant to which the equity holders of Beijing Niudian granted the Company, and Niudian Information or other person upon the designation by the Company, an irrevocable and exclusive option to purchase, at its discretion and to the extent permitted under the PRC law, all or part of the equity holders’ interests in Beijing Niudian at RMB100 or the lowest price that the PRC law permits at the time unless a valuation of the equity is required by the PRC law. The equity holders of Beijing Niudian commit that without the prior written consent of the Company, the equity holders of Beijing Niudian will not, among other things, (i) create any pledge or encumbrance on their equity interests in Beijing Niudian, (ii) transfer or otherwise dispose of their equity interests in Beijing Niudian, (iii) change Beijing Niudian’s registered capital, (iv) amend Beijing Niudian’s articles of association, (v) dispose of Beijing Niudian’s material assets or enter into any material contract with a value of over RMB100,000 (except in the ordinary course of business), or (vi) merge Beijing Niudian with any other entity. In addition, Beijing Niudian undertakes that, without the Company’s prior written consent, it will not, among other things, create any pledge or encumbrance on any of its assets, or transfer or otherwise dispose of its material assets (except in the ordinary course of business). Beijing Niudian and its equity holders shall appoint those individuals recommended by the Company as directors of Beijing Niudian. Beijing Niudian shall provide operating and financial information to the Company at the request of the Company and ensure the continuance of the business. The Exclusive Option Agreement will remain effective until all equity interests in Beijing Niudian held by its equity holders are transferred or assigned to the Company or its designee. Beijing Niudian and its equity holders shall not have any right to terminate the Exclusive Option Agreement.

5) Spousal Consent Letters

The spouses of each of nominee equity holders signed Spousal Consent Letters to consent that the equity interests in Beijing Niudian held by and registered in the name of the respective nominee equity holders will be disposed of pursuant to the VIE Agreements. These spouses agreed not to assert any rights over the equity interest in Beijing Niudian held by their spouses. In addition, in the event that the spouses obtain any equity interests in Beijing Niudian held by their spouses for any reason, they agreed to be bound by the VIE Agreements.

Risks in relation to the VIE structure

In the opinion of the Company’s management, the VIE Agreements have resulted in the Company having the power to direct activities that most significantly impact the VIE, including appointing key management, setting up operating policies, exerting financial controls and transferring profit or assets out of the VIE at its discretion. The Company considers that it has the right to receive all the benefits and assets of the VIE. As the VIE was established as a limited liability company under the PRC law, its creditors do not have recourse to the general credit of the Company for the liabilities of the VIE, and the Company does not have the obligation to assume the liabilities of the VIE.

The Company has determined that the VIE Agreements are in compliance with PRC laws and are legally enforceable. However, uncertainties in the PRC legal system could limit the Company’s ability to enforce the VIE Agreements; and if the equity holders of the VIE were to reduce their interest in the Company, their interests may diverge from that of the Company and that may potentially increase the risk that they would seek to act contrary to the contractual terms.

The Company’s ability to control the VIE also depends on the rights provided to the Company under the Powers of Attorney to vote on all matters requiring equity holders’ approval in the respective VIE. As noted above, the Company believes these Powers of Attorney are legally enforceable but yet they may not be as effective as direct equity ownership. In addition, if the corporate structure of the Group or the contractual arrangements between the Company, Niudian Information, the VIE and its respective equity holders were found to be in violation of any existing PRC laws and regulations, the relevant PRC regulatory authorities could:

revoke the business license and/or operating licenses of such entities;

discontinue or place restrictions or onerous conditions on the Group’s operations;

impose fines, confiscating the income from our VIE, or imposing other requirements with which the Group may not be able to comply;

require the Group to restructure its ownership structure or operations, including terminating the contractual arrangements with the VIE and deregistering the equity pledges of the VIE, which in turn would affect the Company’s ability to consolidate, derive economic interests from, or exert effective control over the VIE; or

restrict or prohibit our use of the proceeds of this offering to finance our business and operations in China.

The imposition of any of the above restrictions or actions may result in a material and adverse effect on the Group’s ability to conduct its business. In addition, if the imposition of any of these restrictions causes the Company to lose the right to direct the activities of the VIE or the right to receive its economic benefits, the Company would no longer be able to consolidate the VIE. The Company’s management believes that the likelihood to lose the Company’s current ownership structure or the contractual arrangements with the VIE is remote based on the current facts and circumstances.

There is no VIE in which the Company has a variable interest but is not the primary beneficiary. Currently there is no contractual arrangement that could require the Company to provide additional financial support to the VIE.

The following consolidated assets and liabilities information of the Group’s VIE as of December 31, 2017 and 2018, and consolidated net revenues, net loss and cash flow information for the years ended December 31, 2016, 2017 and 2018, have been included in the accompanying consolidated financial statements:


	As of December 31,
	2017	2018
	RMB	RMB
Cash	71,792,874	90,723,253
Short-term investments	85,187,718	120,241,425
Accounts receivable, net	10,382,112	54,424,845
Inventories	88,225,965	142,155,411
Prepayments and other current assets	7,349,583	22,711,514
Amounts due from related parties*	—	4,262,270
Total current assets	262,938,252	434,518,718

Property and equipment, net	28,696,602	40,580,352
Intangible assets, net	1,277,467	580,667
Other non-current assets	626,605	16,805,475
Total assets	293,538,926	492,485,212

Short-term bank borrowings	168,234,207	179,978,003
Accounts payable	124,937,465	249,665,890
Amounts due to related parties**	144,169,442	211,250,230
Advances from customers	48,503,389	20,505,861
Deferred revenue—current	9,853,361	12,666,330
Accrued expenses and other current liabilities	75,382,869	119,242,975
Total current liabilities	571,080,733	793,309,289

Warranty—non current	12,378,751	17,609,842
Deferred revenue—non current	144,700	234,801
Total liabilities	583,604,184	811,153,932

 Amounts due from related parties refers to the amounts due from the Company and Niudian Information which are eliminated upon consolidation.

 Amounts due to related parties refers to the amounts due to the Company and Niudian Information which are eliminated upon consolidation.


	For the Year Ended December 31,
	2016	2017	2018
	RMB	RMB	RMB
Net revenues	354,810,048	769,368,001	1,477,593,628
Net loss	(227,081,999)	(145,154,084)	(294,156,973)
Net cash (used in)/provided by operating activities	(80,026,685)	(2,423,156)	14,379,166
Net cash used in investing activities	(59,949,934)	(55,928,949)	(74,333,070)
Net cash provided by financing activities	185,610,980	68,703,310	78,199,492
Effect of foreign currency exchange rate changes on cash	196,441	(813,270)	684,791
Net increase in cash	45,830,802	9,537,935	18,930,379
Cash at the beginning of the year	16,424,137	62,254,939	71,792,874
Cash at the end of the year	62,254,939	71,792,874	90,723,253

The unrecognized revenue-producing assets that are held by the VIE primarily consist of ICP License, Production License for National Industrial Products, trademarks, patents, know-how and customer relationships. None of the assets of the VIE can be used only to settle obligations of VIE. None of the assets of the VIE has been pledged or collateralized. The creditors of the VIE do not have recourse to the general credit of the Company or its consolidated subsidiaries.

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

12 Months Ended

Dec. 31, 2018

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

(a) Basis of presentation

The accompanying consolidated financial statements of the Group have been prepared in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP").

(b) Principles of Consolidation

The consolidated financial statements of the Group have been prepared in accordance with U.S. GAAP. The consolidated financial statements include the financial statements of the Company, its subsidiaries, the VIE for which the Company or its subsidiary is the primary beneficiary, and the VIE’s subsidiaries.

Subsidiaries are those entities in which the Company, directly or indirectly, controls more than one half of the voting power or has the power to govern the financial and operating policies, to appoint or remove the majority of the members of the board of directors, or to cast a majority of votes at the meeting of directors. A VIE is an entity in which the Company, or its subsidiary, through contractual arrangements, exercises effective control over the activities that most impact the economic performance, bears the risks of, and enjoys the rewards normally associated with ownership of the entity, and therefore the Company or its subsidiary is the primary beneficiary of the entity.

All intercompany transactions and balances among the Company, its subsidiaries, the VIE, and the VIE’s subsidiaries have been eliminated upon consolidation.

The preparation of the consolidated financial statements in accordance with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, related disclosures of contingent assets and liabilities at the balance sheet date, and the reported revenues and expenses during the reported period in the consolidated financial statements and accompanying notes. Significant accounting estimates include, but not limited to, the allowance for doubtful accounts receivable, write downs for excess and obsolete inventories, depreciable lives of property and equipment and intangible assets, the realization of deferred income tax assets, future warranty expenses, the fair value of share-based compensation awards and convertible loans, and the fair value of the ordinary shares to determine the existence of beneficial conversion feature of the convertible redeemable preferred shares. Changes in facts and circumstances may result in revised estimates. Actual results could differ from those estimates, and as such, differences may be material to the consolidated financial statements.

(d) Convenience Translation

Translations of balances in the consolidated financial statements from RMB into US$ as of and for the year ended December 31, 2018 are solely for the convenience of the readers and were calculated at the rate of US$1.00=RMB6.8755, representing the noon buying rate in The City of New York for cable transfers of RMB as certified for customs purposes by the Federal Reserve Bank of New York on December 31, 2018. No representation is made that the RMB amounts could have been, or could be, converted, realized or settled into US$ at that rate on December 31, 2018, or at any other rate.

(e) Commitments and Contingencies

In the normal course of business, the Group is subject to loss contingencies, such as legal proceedings and claims arising out of its business, that cover a wide range of matters, including, among others, government investigations, shareholder lawsuits, and non-income tax matters. An accrual for a loss contingency is recognized when it is probable that a liability has been incurred and the amount of loss can be reasonably estimated. If a potential material loss contingency is not probable but is reasonably possible, or is probable but cannot be estimated, then the nature of the contingent liability, together with an estimate of the range of possible loss if determinable and material, is disclosed.

(f) Cash

Cash consist of cash on hand, cash at bank and term deposits, which have original maturities of three months or less and are readily convertible to known amounts of cash. Cash at bank and term deposits are deposited in financial institutions at below locations:


	As of December 31,
	2017	2018
	RMB	RMB
Financial institutions in the mainland of the PRC
—Denominated in RMB	51,157,225	145,529,365
—Denominated in USD	23,525,190	155,583,394
—Denominated in EUR	257	—
Total cash balances held at mainland PRC financial institutions	74,682,672	301,112,759

Financial institutions in the United States
—Denominated in USD	37,307,479	4,038,742
Total cash balances held at the United States financial institutions	37,307,479	4,038,742

Financial institutions in the Hong Kong S.A.R.
—Denominated in USD	—	263,588,286

Total cash balances held at the Hong Kong S.A.R. financial institutions	—	263,588,286
Total cash balances held at financial institutions	111,990,151	568,739,787

(g) Term deposit

Term deposit represents deposit placed with bank with original maturities of more than three months but less than one year. The Group's term deposit is denominated in USD and is deposited at a financial institution in the mainland of the PRC.

(h) Restricted Cash

Restricted cash is an amount of cash deposited with banks in conjunction with borrowings from the banks. Restriction on the use of such cash and the interest earned thereon is imposed by the banks and remains effective throughout the terms of the bank borrowings. Restricted cash that will be released to cash within the next 12 months is classified as current asset, while the remaining balance is classified as non-current asset on the Company’s consolidated balance sheets. The Group’s restricted cash are denominated in USD and are deposited at financial institutions in the mainland of the PRC.

(i) Short-term investments

The Group’s short-term investments represent the Group’s investments in financial products managed by financial institutions in the PRC which are redeemable at the option of the Group on any working day. Short-term investments are reported at fair value, with unrealized holding gains or losses, net of the related tax effect, excluded from earnings and recorded as a separate component of accumulated other comprehensive income/(loss) until realized. Realized gains or losses from the sale of short-term investments are determined on a specific identification basis and are recorded as investment income when earned.

(j) Accounts Receivable

Accounts receivable are recorded at the invoiced amount and do not bear interest. Amounts collected on trade accounts receivable are included in net cash provided by operating activities in the consolidated statements of cash flows. Management considers the following factors when determining the collectability of specific accounts: historical experience, credit worthiness of the clients, aging of the receivables and other specific circumstances related to the accounts. An allowance for doubtful accounts is made and recorded into general and administrative expenses based on aging of accounts receivable and on any specifically identified accounts receivable that may become uncollectible. Accounts receivable which are deemed to be uncollectible are charged off against the allowance after all means of collection have been exhausted and the potential for recovery is considered remote. There is a time lag between when the Group estimates a portion of or the entire account balances to be uncollectible and when a write off of the account balances is taken. The Group does not have any off-balance sheet credit exposure related to its customers.

(k) Inventories

Inventories, consisting of raw materials, work in progress, and products available for sale, are stated at the lower of cost or net realizable value. The cost of inventory is determined using the weighted average cost method. Cost of work-in-process and finished goods comprise direct materials, direct production costs and an allocation of production overheads based on normal operating capacity. The Group takes ownership, risks and rewards of the products purchased. Inventory is written down for damaged and slow-moving goods, which is dependent upon factors such as historical and forecasted consumer demand. When appropriate, write downs to inventory are recorded to write down the cost of inventories to their net realizable value. Write downs of nil, nil and nil were recorded in cost of revenues for the years ended December 31, 2016, 2017 and 2018, respectively.

(l) Property and Equipment, net

Property and equipment are stated at cost less accumulated depreciation and any recorded impairment.

The estimated useful lives are as follows:


Machinery and equipment		3 ~ 10 years
Furniture		3 years
Leasehold improvements		3 years
Office and electronic equipment		2 ~ 5 years
Motor vehicles		4 years

Depreciation on property and equipment is calculated on the straight-line method over the estimated useful lives of the assets.

Depreciation and amortization of property and equipment attributable to manufacturing activities is capitalized as part of inventories, and recognized as cost of revenues when the inventory is sold.

When items are retired or otherwise disposed of, income is charged or credited for the difference between net book value and the proceeds received thereon. Ordinary maintenance and repairs are charged to expense as incurred, and replacements and betterments are capitalized and amortized over the remaining useful life.

(m) Intangible assets

Intangible assets acquired separately are measured on initial recognition at cost. Following initial recognition, intangible assets with finite lives are carried at cost less any accumulated amortization and any accumulated impairment losses.

Intangible assets with finite lives are amortized over the useful economic life on straight-line basis and assessed for impairment whenever there is an indication that the intangible assets may be impaired.

(n) Impairment of Long-lived Assets

Long-lived assets such as property and equipment and intangible assets with finite lives are evaluated for impairment whenever events or changes in circumstances indicate that the carrying value of an asset may not be fully recoverable or that the useful life is shorter than the Group had originally estimated. When these events occur, the Group evaluates the impairment for the long-lived assets by comparing the carrying value of the assets to an estimate of future undiscounted cash flows expected to be generated from the use of the assets and their eventual disposition. If the sum of the expected future undiscounted cash flows is less than the carrying value of the assets, the Group recognizes an impairment loss based on the excess of the carrying value of the assets over the fair value of the assets. No impairment of long-lived assets was recognized for the years ended December 31, 2016, 2017 and 2018.

(o) Value added taxes

The Company’s PRC subsidiaries are subject to value added tax ("VAT"). Revenue from sales of products is generally subject to VAT at the rate of 17% prior to May 1, 2018 and 16% after May 1, 2018, and subsequently paid to PRC tax authorities after netting input VAT on purchases and VAT export rebates. The excess of output VAT over input VAT and VAT export rebates is reflected in Accrued expenses and other current liabilities, and the excess of input VAT and VAT export rebates over output VAT is reflected in Prepayments and other current assets in the consolidated balance sheets.

(p) Fair Value Measurements

Fair value represents the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or a liability.

Accounting guidance defines fair value, establishes a framework for measuring fair value and expands disclosures about fair value measurements. Accounting guidance establishes a three-level fair value hierarchy and requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. A financial instrument’s categorization within the fair value hierarchy is based upon the lowest level of input that is significant to the fair value measurement. The three levels of inputs are:

Level 1—Observable inputs that reflect quoted prices (unadjusted) for identical assets or liabilities in active markets.

Level 2—Include other inputs that are directly or indirectly observable in the marketplace.

Level 3—Unobservable inputs which are supported by little or no market activity.

Accounting guidance also describes three main approaches to measuring the fair value of assets and liabilities: (1) market approach; (2) income approach and (3) cost approach. The market approach uses prices and other relevant information generated from market transactions involving identical or comparable assets or liabilities. The income approach uses valuation techniques to convert future amounts to a single present value amount. The measurement is based on the value indicated by current market expectations about those future amounts. The cost approach is based on the amount that would currently be required to replace an asset.

Financial assets and liabilities of the Group primarily consist of cash, term deposits, restricted cash, short-term investments, accounts receivable, short term bank borrowings, convertible loan, accounts payable and advances from customers. The Group measures short-term investments and convertible loan at fair value on a recurring basis. Short-term investments include financial products issued by financial institutions, which are valued based on prices per units quoted by issuers. They are categorized in Level 2 of the fair value hierarchy. Convertible loan being recognized in its entirety at fair value were measured at fair value using unobservable inputs. They are categorized in Level 3 of the fair value hierarchy. As of December 31, 2017 and 2018, the carrying values of other financial instruments approximated to their fair values due to the short term maturity of these instruments.

The Group’s non-financial assets, such as intangible assets and property and equipment, would be measured at fair value only if they were determined to be impaired.

(q) Revenue recognition

The Group generates substantially all of its revenues from sales of smart electric scooters, accessories and spare parts to the Group’s PRC franchised stores and overseas offline distributors or directly to individual customers online. The Group also generates its revenues from its subscription-based mobile application services, as well as insurance service as an agent. The Group recognizes revenue when persuasive evidence of an arrangement exists, delivery has occurred and the services have been rendered, the sales price is fixed or determinable, and collection is reasonably assured.

When the Group sells its smart electric scooters to its customers, it also provides mobile application services for free for one to two years (the "free service period"). Customers are able to locate their smart electric scooters, as well as obtain the operating status (e.g. battery status), and claim online repair and maintenance requests of their smart electric scooters, upon their registration of their smart electric scooters on the Group’s mobile application. Customers may subscribe to such service after the free service period if they want to continue using aforementioned functions.

The Group allocates revenue to all deliverables based on their relative selling prices. The Group uses a hierarchy to determine the selling price to be used for allocating revenue to the deliverables: (i) vendor-specific objective evidence ("VSOE") of fair value, (ii) third-party evidence ("TPE"), and (iii) best estimate of the selling price ("BESP"). The Group uses the standalone selling price as the fair value of VSOE for advanced mobile application services. The allocated revenue to mobile application services is deferred and recognized over the free service period. The deferred revenue that will be recognized in the next twelve months is classified as current portion, and the remaining balance of deferred revenue is classified as non-current portion.

Revenue from sales of products is recognized when the products is accepted by the franchised stores, overseas offline distributors or individual customers. When the Group sells its products to its franchised stores for domestic sales in PRC, acceptance of the products by the franchised stores is evidenced by goods receipt notes signed by the franchised stores, which is generally at the Group’s warehouse. The Group has no remaining obligations upon the franchised stores acceptance of the products. The risks and rewards of ownership of the products is transferred to the franchised stores upon the signing of the goods receipt notes and the franchised stores have no rights to return the products. When the Group sells its products to distributors for oversea sales, risks and rewards of ownership are transferred to the distributors upon the products are delivered to and accepted by distributors at the named port of shipment. When the Group sells its products to individual customers through its own online store and third-party e-commerce platform, the Group is responsible for the delivery to individual customers. Acceptance of the products is evidenced by goods receipt notes signed by individual customers, which represents the risks and rewards of ownership are transferred to individual customers. The Group offers 7‑day return-and-refund policy to individual customers who purchase products online.

Revenue is recognized net of sales volume rebate, return allowances and VAT. The Group provides sales volume rebate to qualified distributors based on the volume sold by such distributors in a certain period. Sales volume rebates are accrued, when the products are sold to distributors. Return allowances, which reduce net revenues, are estimated based on historical experiences. Sales returns were insignificant for the years ended December 31, 2016, 2017 and 2018.

The Group also sells insurance plan for electric scooters ("NIU Cover") to individual customers at their option. The insurance is provided by third party insurance companies. The Group earns the service fee on net basis. The Group recognizes revenue when the insurance agreement is signed, since the Group bears no further obligation upon the agreements are entered into between individual customers and insurance providers.

For some sales, the Group collects cash before delivery. Cash collected before product delivery is recognized as advances from customers.

(r) Warranties

The Group provides for the estimated costs of warranties at the time revenue is recognized. The specific terms and conditions of those warranties vary among different parts of electric scooters. Factors that affect the Group’s warranty obligation include product defect rates and costs of repair or replacement. These factors are estimates that may change based on new information that becomes available each period. The portion of the warranty reserve expected to be incurred within the next 12 months is included within Accrued expenses and other current liabilities while the remaining balance is included within Warranty—non current on the consolidated balance sheets.

(s) Cost of Revenues

Cost of revenues mainly consists of the cost of products sold, write-downs of inventories, logistics costs and warranty costs.

(t) Selling and Marketing Expenses

Selling and marketing expenses mainly consist of advertising costs, promotion expenses and payroll and related expenses for personnel engaged in selling and marketing activities. Advertising expenses, which consist primarily of online and offline advertisements, are expensed when the services are received. The advertising expenses were RMB51,170,420, RMB28,345,034 and RMB76,791,991 for the years ended December 31, 2016, 2017 and 2018, respectively.

(u) General and Administrative Expenses

General and administrative expenses mainly consist of payroll and related costs for employees involved in general corporate functions, professional fees and other general corporate expenses, as well as expenses associated with the use by these functions of facilities and equipment, such as rental and depreciation expenses.

(v) Research and Development Expenses

Research and development expenses mainly consist of payroll and related costs for employees involved in researching and developing new products and technologies, and outsourced design expenses as well as expenses associated with the use by these functions of facilities and equipment, such as rental and depreciation expenses. Research and development expenses are expensed as incurred.

(w) Government Grants

Government grants represent amounts granted by local government authorities as an incentive for companies to promote economic development of the local technology industry. Government grants received by the Group were nonrefundable and were for the purpose of giving immediate incentive with no future costs or obligations were recognized in earnings in the Company’s consolidated statements of comprehensive loss.

(x) Share-based Compensation

The Company periodically grants share-based awards, including but not limited to, restricted ordinary shares, restricted share units, and share options to eligible employees and directors.

Share-based awards granted to employees and directors are measured at the grant date fair value of the awards, and are recognized as compensation expense using the straight-line method over the requisite service period, which is generally the vesting period. For the years ended December 31, 2016 and 2017, the Company estimated forfeitures at the time of grant and revised in the subsequent periods if actual forfeitures differ from those estimates. Effective from January 1, 2018, forfeitures are accounted when they occur.

A change in any of the terms or conditions of share-based awards is accounted for as a modification of the awards. The Group calculates incremental compensation cost of a modification as the excess of the fair value of the modified awards over the fair value of the original awards immediately before its terms are modified at the modification date. For vested awards, the Group recognizes incremental compensation cost in the period the modification occurs. For awards not being fully vested, the Group recognizes the sum of the incremental compensation cost and the remaining unrecognized compensation cost for the original awards over the remaining requisite service period after modification.

Share-based compensation in relation to the restricted ordinary shares and restricted share units is measured based on the fair value of the Company's ordinary shares at the grant date of the award. Prior to the IPO, the fair value was estimated using the income approach and equity allocation method. Estimation of the fair value of the Company's ordinary shares involves significant assumptions that might not be observable in the market, and a number of complex and subjective variables, including the expected share price volatility (approximated by the volatility of comparable companies), discount rate, risk-free interest rate and subjective judgments regarding the Company's projected financial and operating results, its unique business risks, the liquidity of its ordinary shares and its operating history and prospects at the time the grants are made. After the IPO, the fair value is the closing prices of the Company’s stock traded in the open market as of the grant date. Share-based compensation in relation to the share options is estimated using the Binominal Option Pricing Model. The determination of the fair value of share options is affected by the share price of the Company's ordinary shares as well as the assumptions regarding a number of complex and subjective variables, including the expected share price volatility, risk-free interest rate, exercise multiple and expected dividend yield. The fair value of these awards was determined with the assistance from a valuation report prepared by an independent valuation firm using management's estimates and assumptions.

(y) Employee Benefits

The Company’s subsidiaries and the VIE and VIE’s subsidiaries in PRC participate in a government mandated, multiemployer, defined contribution plan, pursuant to which certain retirement, medical, housing and other welfare benefits are provided to employees. PRC labor laws require the entities incorporated in China to pay to the local labor bureau a monthly contribution calculated at a stated contribution rate on the monthly basic compensation of qualified employees. The Group has no further commitments beyond its monthly contribution. Employee social benefits included as cost of products and expenses in the accompanying consolidated statements of comprehensive loss amounted to RMB12,652,658, RMB13,705,669 and RMB15,544,106 for the years ended December 31, 2016, 2017 and 2018, respectively.

(z) Income Taxes

Current income taxes are provided on the basis of net income/(loss) for financial reporting purposes, and adjusted for income and expense items which are not assessable or deductible for income tax purposes, in accordance with the regulations of the relevant tax jurisdictions. Deferred income taxes are provided using the liability method. Under this method, deferred income tax assets and liabilities are recognized for the tax effects of temporary differences and are determined by applying enacted statutory tax rates that will be in effect in the period in which the temporary differences are expected to reverse to the temporary differences between the financial statements’ carrying amounts and the tax bases of assets and liabilities. A valuation allowance is provided to reduce the amount of deferred income tax assets if based on the weight of available evidence, it is more-likely-than-not that some portion, or all, of the deferred income tax assets will not be realized. The effect on deferred income taxes arising from a change in tax rates is recognized in the consolidated statements of comprehensive loss in the period of change.

The Group applies a "more likely than not" recognition threshold in the evaluation of uncertain tax positions. The Group recognizes the benefit of a tax position in its consolidated financial statements if the tax position is "more likely than not" to prevail based on the facts and technical merits of the position. Tax positions that meet the "more likely than not" recognition threshold are measured at the largest amount of tax benefit that has a greater than fifty percent likelihood of being realized upon settlement. Unrecognized tax benefits may be affected by changes in interpretation of laws, rulings of tax authorities, tax audits, and expiry of statutory limitations. In addition, changes in facts, circumstances and new information may require the Group to adjust the recognition and measurement estimates with regard to individual tax positions. Accordingly, unrecognized tax benefits are periodically reviewed and re-assessed. Adjustments, if required, are recorded in the Group’s consolidated financial statements in the period in which the change that necessities the adjustments occur. The ultimate outcome for a particular tax position may not be determined with certainty prior to the conclusion of a tax audit and, in certain circumstances, a tax appeal or litigation process. The Group records interest and penalties related to unrecognized tax benefits (if any) in interest expenses and general and administrative expenses, respectively. As of December 31, 2017 and 2018, the Group did not have any significant unrecognized uncertain tax positions.

(aa) Operating leases

The Group leases premises for offices and production lines under non-cancellable operating leases. Leases with escalated rent provisions are recognized on a straight-line basis commencing with the beginning of the lease term.

(bb) Foreign currency translation and foreign currency risks

The Company’s reporting currency is Renminbi ("RMB"). The functional currency of the Company and its subsidiary incorporated at Hong Kong S.A.R. is the United States dollars ("US$"). The functional currency of the Company’s PRC subsidiary, VIE and VIE’s subsidiaries is the RMB.

Transactions denominated in currencies other than the functional currency are remeasured into the functional currency at the exchange rates prevailing at the dates of the transactions. Monetary assets and liabilities denominated in a foreign currency are remeasured into the functional currency using the applicable exchange rate at the balance sheet date. The resulted exchange differences are recorded as foreign currency exchange gain or losses in the consolidated statements of comprehensive loss.

The financial statements of the Company and its subsidiary incorporated at Hong Kong S.A.R. are translated from the functional currency into RMB. Assets and liabilities are translated into RMB using the applicable exchange rates at the balance sheet date. Equity accounts other than earnings (deficits) generated in the current period are translated into RMB using the appropriate historical rates. Revenues, expenses, gains and losses are translated into RMB using the average exchange rates for the relevant period. The resulted foreign currency translation adjustments are recorded as a component of other comprehensive income or losses in the consolidated statements of comprehensive loss, and the accumulated foreign currency translation adjustments are recorded as a component of accumulated other comprehensive income or losses in the consolidated statements of changes in shareholders’ (deficit)/equity.

The RMB is not a freely convertible currency. The PRC State Administration for Foreign Exchange, under the authority of the PRC government, controls the conversion of RMB to foreign currencies. The value of the RMB is subject to changes of central government policies and international economic and political developments affecting supply and demand in the China foreign exchange trading system market.

(cc) Concentration and risk

Concentration of customers and suppliers

No customers individually represent greater than 10% of total net revenues of the Group for the years ended December 31, 2016, 2017 and 2018.

Suppliers from whom individually represent greater than 10% of total purchases of the Group for the years ended December 31, 2016, 2017 and 2018, are as follows:


	For the Year ended December 31,
	2016			2017			2018
	RMB	%		RMB	%		RMB	%
Supplier F	*	*		*	*		193,555,999	15	%
Supplier A	51,368,000	12	%	187,065,077	21	%	150,385,652	12	%
Supplier B	61,900,615	14	%	152,966,930	18	%	*	*
Supplier C	60,072,473	14	%	*	*		*	*

Customers accounting for 10% or more of accounts receivable, net are as follows:


	As of December 31,
	2017			2018
	RMB	%		RMB	%
Customer Y	3,904,087	32	%	45,980,177	84	%
Customer Z	1,471,144	12	%	*	*

Customers accounting for 10% or more of advances from customers are as follows:


	As of December 31,
	2017			2018
	RMB	%		RMB	%
Customer V	9,021,739	19	%	*	*

Suppliers accounting for 10% or more of accounts payable are as follows:


	As of December 31,
	2017			2018
	RMB	%		RMB	%
Supplier E	*	*		26,483,893	11	%
Supplier F	*	*		25,702,037	10	%
Supplier B	17,048,400	14	%	*	*
Supplier D	12,623,108	10	%	*	*

The amount was less than 10% of total balance.

Concentration of credit risk

Financial instruments that potentially expose the Group to concentrations of credit risk consist principally of cash, term deposits, restricted cash, short-term investments and accounts receivable.

The Group's investment policy requires cash, term deposits, restricted cash and short-term investments to be placed with high-quality financial institutions and to limit the amount of credit risk from any one issuer. The Group regularly evaluates the credit standing of the counterparties or financial institutions.

The Group conducts credit evaluations on its customers prior to delivery of goods or services. The assessment of customer creditworthiness is primarily based on historical collection records, research of publicly available information and customer on-site visits by senior management. Based on this analysis, the Group determines what credit terms, if any, to offer to each customer individually. If the assessment indicates a likelihood of collection risk, the Company will not deliver the services or sell the products to the customer or require the customer to pay cash, post letters of credit to secure payment or to make significant down payments.

Interest rate risk

The Group’s short-term bank borrowing bears interests at fixed rates. If the Group were to renew these loans, the Group might be subject to interest rate risk.

(dd) Earnings/(Loss) per Share

Basic earnings/(loss) per share is computed by dividing net income/(loss) attributable to holders of ordinary shares, considering the accretions to redemption value of the preferred shares (if any), by the weighted average number of ordinary shares outstanding during the year using the two-class method. Under the two-class method, any net income is allocated between ordinary shares and other participating securities based on their participating rights. A net loss is not allocated to participating securities when the participating securities does not have contractual obligation to share losses.

The Company's preferred shares and restricted ordinary shares are participating securities. The preferred shares are participating securities as they participate in undistributed earnings on an as-if-converted basis and the restricted ordinary shares are participating securities as the holders of the restricted ordinary shares have a non-forfeitable right to receive dividends with all ordinary shares. Neither the preferred shares nor the restricted ordinary shares have a contractual obligation to fund or otherwise absorb the Group's losses. Accordingly, any undistributed net income is allocated on a pro rata basis to ordinary shares, preferred shares and restricted ordinary shares; whereas any undistributed net loss is allocated to ordinary shares only.

Restricted ordinary shares are excluded from the weighted average number of ordinary shares outstanding because the restricted ordinary shareholders must return the restricted ordinary shares to the Company, if the specified condition are not met.

Diluted earnings/(loss) per share is calculated by dividing net income/(loss) attributable to ordinary shareholders, as adjusted for the accretion and allocation of net income related to the preferred shares, if any, by the weighted average number of ordinary and dilutive ordinary equivalent shares outstanding during the period. Ordinary equivalent shares consist of shares issuable upon the conversion of the preferred shares and convertible loan using the if-converted method, restricted ordinary shares and ordinary shares issuable upon the exercise of outstanding share option and restricted share units (using the treasury stock method). Ordinary equivalent shares are calculated based on the most advantageous conversion rate or exercise price from the standpoint of the security holder. Ordinary equivalent shares are not included in the denominator of the diluted earnings per share calculation when inclusion of such shares would be anti-dilutive.

(ee) Segment Reporting

The Company’s chief operating decision maker has been identified as the Chief Executive Officer, who reviews consolidated results when making decisions about allocating resources and assessing performance of the Group. For the purpose of internal reporting and management’s operation review, the Company’s Chief Executive Officer and management personnel do not segregate the Group’s business by product. All products and services are viewed as in one and the only operating segment.

(ff) Statutory Reserves

In accordance with the PRC Company Laws, the Group’s PRC subsidiary, VIE and VIE’s subsidiaries must make appropriations from their after-tax profits as determined under the generally accepted accounting principles in the PRC ("PRC GAAP") to non-distributable reserve funds including statutory surplus fund and discretionary surplus fund. The appropriation to the statutory surplus fund must be 10% of the after-tax profits as determined under PRC GAAP. Appropriation is not required if the statutory surplus fund has reached 50% of the registered capital of the PRC companies. Appropriation to the discretionary surplus fund is made at the discretion of the PRC companies.

The statutory surplus fund and discretionary surplus fund are restricted for use. They may only be applied to offset losses or increase the registered capital of the respective companies. These reserves are not allowed to be transferred to the Company by way of cash dividends, loans or advances, nor can they be distributed except for liquidation.

For the years ended December 31, 2016, 2017 and 2018, no appropriation was made to the statutory surplus fund and discretionary surplus fund by the Group’s PRC subsidiary, VIE and VIE’s subsidiaries as these PRC companies did not earn any after-tax profits as determined under PRC GAAP.

(gg) Recent Accounting Pronouncements

In August 2015, FASB issued Accounting Standards Update ("ASU") No. 2015‑14, Revenue from Contracts with Customers—Deferral of the effective date ("ASU 2015‑14"). The amendments in ASU 2015‑14 defer the effective date of ASU No. 2014‑09, Revenue from Contracts with Customers, ("ASU 2014‑09"), issued in May 2014. According to the amendments in ASU 2015‑14, for public business entity, the new revenue guidance ASU 2014‑09 is effective for annual reporting periods beginning after December 15, 2017, including interim reporting periods within that reporting period. Earlier application is permitted only as of annual reporting periods beginning after December 15, 2016, including interim reporting periods within that reporting period. For all other entities, ASU 2014‑09 is effective for annual reporting periods beginning after December 15, 2018, and interim reporting periods within annual reporting periods beginning after December 15, 2019. In March 2016, the FASB issued ASU No. 2016‑08, Revenue from Contracts with Customers—Principal versus Agent Considerations ("ASU 2016‑08"), which clarifies the implementation guidance on principal versus agent considerations. In April 2016, the FASB issued ASU No. 2016‑10, Revenue from Contracts with Customers—Identifying Performance Obligations and Licensing ("ASU 2016‑10"), which clarify guidance related to identifying performance obligations and licensing implementation guidance contained in ASU No. 2014‑09. In May 2016, the FASB issued ASU No. 2016‑12, Revenue from Contracts with Customers—Narrow-Scope Improvements and Practical Expedients ("ASU 2016‑12"), which addresses narrow-scope improvements to the guidance on collectability, non-cash consideration, and completed contracts at transition and provides practical expedients for contract modifications at transition and an accounting policy election related to the presentation of sales taxes and other similar taxes collected from customers. The effective date for the amendment in ASU 2016‑08, ASU 2016‑10 and ASU 2016‑12 are the same as the effective date of ASU No. 2014‑09. All guidance is collectively referred to as “ASC606”. As the Company is an "emerging growth company" and elects to apply for the new and revised accounting standards at the effective date for a private company, ASC606 will be applied for the fiscal year ending December 31, 2019. The standard may be applied retrospectively to each prior period presented or retrospectively with the cumulative effective effect recognized as of the date of adoption (“modified retrospective method”). The Company has selected to apply the modified retrospective method. The Company has evaluated the impact of ASC606 on the specific areas that apply to the Company and their potential impact to its processes, accounting, financial reporting, disclosures, and controls. Based on the contracts outstanding as of December 31, 2018, the Company has determined that the overall impact of adopting this ASC606 will not be material to the Company's consolidated financial statements. ASC606 will primarily involve updating revenue recognition policy and related documentation and expanding revenue disclosures in the Company's consolidated financial statements.

In February 2016, the FASB issued ASU No. 2016‑02 ("ASU 2016‑02"), Leases (Topic 842). ASU 2016-02 is intended to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. Additionally, the ASU will require disclosures to help investors and other financial statement users better understand the amount, timing, and uncertainty of cash flows arising from leases, including qualitative and quantitative requirements. The update requires lessees to apply a modified retrospective approach for recognition and disclosure, beginning with the earliest period presented. In July 2018, the FASB issued ASU No. 2018-11, "Leases (Topic 842)"-Targeted Improvements, which allows an additional transition method to adopt the new lease standard at the adoption date, as compared to the beginning of the earliest period presented, and recognize a cumulative-effect adjustment to the beginning balance of retained earnings in the period of adoption. Topic 842 is effective for public companies for annual reporting periods, and interim periods within those years beginning after December 15, 2018. For all other entities, it is effective for fiscal years beginning after December 15, 2019, and interim periods within fiscal years beginning after December 15, 2020. Early adoption is permitted. As the Company is an "emerging growth company" and elects to apply for the new and revised accounting standards at the effective date for a private company, ASU 2016‑02 will be applied for the fiscal year ending December 31, 2020. The Company is currently evaluating the impact of adopting this standard on its consolidated financial statements.

In March 2016, the FASB issued ASU No. 2016‑09, Compensation—Stock Compensation: Improvements to Employee Share-Based Payment Accounting, which relates to the accounting for employee share-based payments. This standard addresses several aspects of the accounting for share-based payment award transactions, including: (a) income tax consequences; (b) classification of awards as either equity or liabilities; (c) forfeitures accounting; and (d) classification on the statement of cash flows. For public entities, this standard will be effective for fiscal years beginning after December 15, 2016, including interim periods within those fiscal years. For all other entities, this standard is effective for annual periods beginning after December 15, 2017, and interim periods within annual periods beginning after December 15, 2018. The Company adopted this ASU beginning January 1, 2018 and selected to account for forfeitures when they occur. Such amendment was applied using the modified retrospective method and did not have material impact on the consolidated financial statements.

In November 2016, the FASB issued ASU No. 2016‑18, Statement of Cash Flows (Topic 230): Restricted Cash. This ASU requires that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Therefore, amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. The amendments in this Update apply to all entities that have restricted cash or restricted cash equivalents and are required to present a statement of cash flows under Topic 230. The amendments in this Update are effective for public business entities for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. For all other entities, the amendments are effective for fiscal years beginning after December 15, 2018, and interim periods within fiscal years beginning after December 15, 2019. Early adoption is permitted, including adoption in an interim period. If an entity early adopts the amendments in an interim period, any adjustments should be reflected as of the beginning of the fiscal year that includes that interim period. The Company adopted this ASU on January 1, 2019, resulting in restricted cash being combined with cash reconciling beginning and ending balances.

In June 2018, the FASB issued ASU No. 2018‑07, Compensation—Stock Compensation (Topic 718), which simplifies the accounting for share-based payments granted to nonemployees for goods and services. Under the ASU, most of the guidance on such payments to nonemployees would be aligned with the requirements for share-based payments granted to employees. For public entities, this standard will be effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. For all other entities, this standard is effective for annual periods beginning after December 15, 2019, and interim periods within annual periods beginning after December 15, 2020. Early adoption is permitted, but no earlier than an entity’s adoption date of Topic 606. Management is currently evaluating the impact of this amendment and does not plan to early adopt this guidance.

In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement. ASU 2018-13 modifies certain disclosure requirements on fair value measurements, including (i) clarifying narrative disclosure regarding measurement uncertainty from the use of unobservable inputs, if those inputs reasonably could have been different as of the reporting date, (ii) adding certain quantitative disclosures, including (a) changes in unrealized gains and losses for the period included in other comprehensive income for recurring Level 3 fair value measurements held at the end of the reporting period and (b) the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and (iii) removing certain fair value measurement disclosure requirements, including (a) the amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy, (b) the policy for timing of transfers between levels of the fair value hierarchy and (c) the valuation processes for Level 3 fair value measurements. The amendments in ASU 2018-13 are effective for all entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. The Company is permitted to early adopt any removed or modified disclosures and delay adoption of the additional disclosures until their effective date. The Company is currently evaluating the effect of the disclosure requirements of ASU 2018-13 will have on its consolidated financial statements and does not expect the impact to be material.

SHORT-TERM INVESTMENTS

12 Months Ended

Dec. 31, 2018

SHORT-TERM INVESTMENTS

SHORT-TERM INVESTMENTS

3. SHORT-TERM INVESTMENTS

Short-term investments consisted of the following:


	As of December 31,
	2017	2018
	RMB	RMB
Aggregate cost basis	85,000,000	120,000,000
Gross unrealized holding gain	187,718	241,425
Aggregate fair value	85,187,718	120,241,425

The Group’s short-term investments represent wealth management products issued by commercial banks in the PRC which are redeemed upon demand of the Group. The wealth management products are invested in debt securities issued by the PRC government, corporate debt securities, bank deposits, central bank bills and other securities issued by other financial institutions. As of December 31, 2017 and 2018, there were no gross unrealized holding losses.

ACCOUNTS RECEIVABLES, NET

12 Months Ended

Dec. 31, 2018

ACCOUNTS RECEIVABLES, NET

ACCOUNTS RECEIVABLES, NET

4. ACCOUNTS RECEIVABLES, NET

Accounts receivables, net consisted of the following:


	As of December 31,
	2017	2018
	RMB	RMB
Accounts receivable	12,338,357	54,652,991
Allowance for doubtful accounts	(1,956,245)	(228,146)
Accounts Receivable, net	10,382,112	54,424,845

The movement of the allowance for doubtful accounts is as follows:


	For the Year Ended
	December 31,
	2016	2017	2018
	RMB	RMB	RMB
Balance at the beginning of the year	—	47,846	1,956,245
Additions/(reversals) charged to bad debt expense	47,846	1,908,399	(1,215,464)
Write-off of bad debt allowance	—	—	(512,635)
Balance at the end of the year	47,846	1,956,245	228,146

- Definition

The entire disclosure for claims held for amounts due a entity, excluding financing receivables. Examples include, but are not limited to, trade accounts receivables, notes receivables, loans receivables. Includes disclosure for allowance for credit losses.

+ References + Details

INVENTORIES

12 Months Ended

Dec. 31, 2018

INVENTORIES

INVENTORIES

5. INVENTORIES

Inventories consisted of the following:


	As of December 31,
	2017	2018
	RMB	RMB
Raw materials	72,473,857	120,290,456
Works in progress	1,522,033	1,948,838
Finished goods	14,230,075	20,142,911
Inventories	88,225,965	142,382,205

On April 5, 2018, there was a fire accident incurred at the warehouse in the Group's rented plant facility in Jiangsu Province of People Republic of China. RMB18,254,406 inventories damage loss was recognized in general and administrative expenses for the year ended December 31, 2018.

PREPAYMENTS AND OTHER CURRENT ASSETS

12 Months Ended

Dec. 31, 2018

PREPAYMENTS AND OTHER CURRENT ASSETS

PREPAYMENTS AND OTHER CURRENT ASSETS

6. PREPAYMENTS AND OTHER CURRENT ASSETS

Prepayments and other current assets consisted of the following:


	As of December 31,
	2017	2018
	RMB	RMB
Advances to suppliers	2,772,494	15,507,866
Deductible input VAT and VAT rebates receivable	3,469,724	7,855,998
Staff advances	1,029,409	447,791
Others*	77,956	3,108,299
Prepayments and Other Current Assets	7,349,583	26,919,954

Others mainly include prepaid custom duties and interest income receivables.

PROPERTY AND EQUIPMENT, NET

12 Months Ended

Dec. 31, 2018

PROPERTY AND EQUIPMENT, NET

PROPERTY AND EQUIPMENT, NET

7. PROPERTY AND EQUIPMENT, NET

Property and equipment consisted of the following:


	As of December 31,
	2017	2018
	RMB	RMB
Machinery and equipment	17,453,885	22,615,657
Furniture	15,499,944	36,630,720
Office and electronic equipment	7,253,743	9,071,471
Leasehold improvement	1,897,392	2,116,266
Motor vehicles	454,647	802,251
Property and Equipment	42,559,611	71,236,365
Less: Accumulated depreciation	(13,863,009)	(30,251,191)
Property and Equipment, net	28,696,602	40,985,174

Depreciation expenses were RMB4,490,972, RMB9,049,769 and RMB16,808,987 for the years ended December 31, 2016, 2017 and 2018, respectively.

Depreciation expense on property and equipment was allocated to the following expense items:


	For the Year ended December 31,
	2016	2017	2018
	RMB	RMB	RMB
Cost of revenues	2,405,046	4,217,126	4,638,662
General and administrative expenses	1,120,533	1,873,711	2,261,620
Selling and marketing expenses	264,665	2,646,204	9,438,501
Research and development expenses	700,728	312,728	470,204
Total depreciation expense	4,490,972	9,049,769	16,808,987

INTANGIBLE ASSETS, NET

12 Months Ended

Dec. 31, 2018

INTANGIBLE ASSETS, NET

INTANGIBLE ASSETS, NET

8. INTANGIBLE ASSETS, NET

Intangible assets consisted of the following:


	As of December 31, 2017
		Gross		Net
	Amortization	carrying	Accumulated	carrying
RMB	period	amount	amortization	amount
Domain name	5 years	3,484,000	(2,206,533)	1,277,467


	As of December 31, 2018
		Gross		Net
	Amortization	carrying	Accumulated	carrying
RMB	period	amount	amortization	amount
Trademarks	5 years	8,564,505	(1,427,418)	7,137,087
Domain name	5 years	3,484,000	(2,903,333)	580,667
Total		12,048,505	(4,330,751)	7,717,754

Amortization expenses of RMB696,800, RMB696,800 and RMB2,072,389 were recognized in general and administrative expenses for the years ended December 31, 2016, 2017 and 2018, respectively.

As of December 31, 2018, estimated amortization expense of the existing intangible assets for each of the next five years is RMB2,293,568, RMB1,712,901, RMB1,712,901, RMB1,712,901 and RMB285,483, respectively.

OTHER NON-CURRENT ASSETS

12 Months Ended

Dec. 31, 2018

OTHER NON-CURRENT ASSETS

OTHER NON-CURRENT ASSETS

9. OTHER NON-CURRENT ASSETS

Other non-current assets consisted of the following:


	As of December 31,
	2017	2018
	RMB	RMB
Prepayments for land use right	—	12,329,652
Others*	626,605	4,475,822

Other non-current assets	626,605	16,805,474

Others mainly include prepayments for equipment and intangible assets.

SHORT-TERM BANK BORROWINGS AND RESTRICTED CASH

12 Months Ended

Dec. 31, 2018

SHORT-TERM BANK BORROWINGS AND RESTRICTED CASH

SHORT-TERM BANK BORROWINGS AND RESTRICTED CASH

10. SHORT-TERM BANK BORROWINGS AND RESTRICTED CASH


	As of December 31,
	2017	2018
	RMB	RMB
East West Bank loan	98,234,207	99,978,003
Bank of China loan	10,000,000	20,000,000
SPD Silicon Valley Bank loan	60,000,000	60,000,000
Short-term bank borrowings	168,234,207	179,978,003

In December 2015 and March 2016, Jiangsu Xiaoniu Diandong Technology Co., Ltd. ("Jiangsu Xiaoniu"), a subsidiary of Beijing Niudian, entered into two line-of-credit agreements with East West Bank that provides a one-year term revolving credit facility up to RMB100,000,000 in aggregate with interest rate of 2.8% per annum. All drawdowns are due one year from the drawdown date. To collateralize these lines of credits, the Company and Niu Technologies Group Limited, a subsidiary of the Company incorporated in Hong Kong S.A.R., made deposits of US$16,000,000 in aggregate at East West Bank. In November 2016, the Group signed amended agreements with East West Bank and extended the maturity date of both lines of credits and their collateral to May 29, 2018. In December 2017, the Group further signed amended agreements with East West Bank and extended the maturity date of both lines of credits and their collateral to December 23, 2018 and increased the interest rate to 4.5% per annum. In October 2018, the Group further signed amended agreements with East West Bank and extended the maturity date of both lines of credits to April 15, 2020 and increased the interest rate to 4.75% per annum. The Group can apply for withdrawing the restricted cash when borrowing drawdowns are repaid. As of December 31, 2017 and 2018, total outstanding balances of these loans were RMB98,234,207 and RMB99,978,003, respectively. Total outstanding balances of restricted cash were equivalent to RMB104,547,200 and RMB109,811,200, respectively, and was classified as current assets.

In August 2017, Jiangsu Xiaoniu Diandong Technology Co., Ltd. (“Jiangsu Xiaoniu”) entered into a short-term bank borrowing agreement with Bank of China (the "2017 BOC Loan") that provides a six‑month RMB10,000,000 loan bearing interest at 4.5675% per annum. Mr. Yi’nan Li, the founder and a board member of the Company until June 8, 2018, Mr. Changlong Sheng, a shareholder the Company, Beijing Niudian and its subsidiary Shanghai Niudian Trading Co., Ltd., and Jiangsu Xiaoniu’s subsidiary Changzhou Niudian International Trading Co., Ltd. provided joint liability guaranties for the loan. On February 5, 2018, Jiangsu Xiaoniu fully repaid the 2017 BOC Loan. On February 8, 2018, Jiangsu Xiaoniu obtained a new one-year short-term bank borrowing of RMB20,000,000, which bears interest rate at 4.5675% per annum, from Bank of China (the "2018 BOC Loan"). The guaranties for this loan are as same as the 2017 BOC Loan. The loan was fully repaid by Jiangsu Xiaoniu in December 2018. In December 2018, Jiangsu Xiaoniu obtained a new one-year short-term bank borrowing of RMB20,000,000, which bears interest at a rate of 4.5675% per annum, from Bank of China (the "2019 BOC Loan"). The guarantees for this loan are the same as for the previous loan in February 2018. As of December 31, 2018, the outstanding balance of this loan was RMB20,000,000.

In November 2017, Jiangsu Xiaoniu entered into a line-of-credit agreement with SPD Silicon Valley Bank that provides a one-year term credit facility of up to RMB60,000,000. The interest rate of the loan is at standard rate published by People’s Bank of China. To collateralize this line of credit, the Company made deposits of US$10,000,000 at the bank which will remain restricted until February 7, 2019. In November 2018, the line-of-credit agreement was amended to extend the maturity date to March 15, 2019. The Company continued the deposits of US$10,000,000 at the bank which remained restricted until March 14, 2019. This line of credit contains certain financial and nonfinancial covenants. As of December 31, 2017 and 2018, Jiangsu Xiaoniu was in compliance with the covenants and the outstanding balance was both RMB60,000,000 bearing interest at 4.35% per annum. Outstanding balance of current restricted cash as of December 31, 2017 and 2018 was nil and RMB69,451,514. Outstanding balance of non-current restricted cash as of December 31, 2017 and 2018 was RMB65,342,000 and nil, respectively.

CONVERTIBLE LOAN	12 Months Ended
CONVERTIBLE LOAN	Dec. 31, 2018
CONVERTIBLE LOAN
CONVERTIBLE LOAN	11. CONVERTIBLE LOAN On December 16, 2016, the Company entered a convertible loan agreement (the "2016 Convertible Loan") with Glory Achievement Fund Limited, GGV Capital V L.P., GGV Capital V Entrepreneurs Fund L.P., Hyperfinite Galaxy Holding Limited, Plum Angel Investment Co., Ltd., and Future Capital Discovery Fund I, L.P. (collectively "2016 Convertible Loan Holders") to obtain a loan of US$16,827,000 (equivalent to RMB115,808,672) in aggregate with one-year term. 2016 Convertible Loan Holders are entitled to an option to convert all or part of the outstanding principal of the 2016 Convertible Loan to the Company’s preferred shares upon next round of financing. The interest rate of 2016 convertible loan is 5% per annum provided that no interest shall be accrued on the outstanding principal amount, if the entire or any portion of the principal amount is converted to the Company’s preferred shares. The conversion price shall be the per share price based on valuation of the Company at 80% of lower of US$260,400,000 or the pre-money valuation in the next round financing. If the conversion price is based on a valuation equal to 80% of US$260,400,000, the 2016 convertible loan shall be converted to Series A‑3 Preferred Shares. If the conversion price is based on a valuation lower than 80% of US$260,400,000, the 2016 Convertible Loan shall be converted to preferred shares with the same terms and the same rights and obligation as the preferred shares any new investors may have in the next round of financing. As the conversion price was not determinable at the issuance date, there was no noncontingent beneficial conversion feature. As such, the 2016 Convertible Loan was not in whole or in part classified as a component of equity. The Company elected to measure the 2016 Convertible Loan in its entirety at fair value with amount of changes in fair value recognized in earnings in consolidated statements of comprehensive loss. The Company adopted a scenario-weighted average method to estimate the fair value of the convertible loan as of December 31, 2017 and the conversion date based on the probability of each scenario and pay-off of convertible loan under each scenario. The scenarios include different timing of next round financing and corresponding conversion price of the convertible loan. The 2016 Convertible Loan was converted to 10,119,329 Series A‑3 Preferred Shares at the price of US$1.66 per share on March 26, 2018 (Note 13).

ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES

12 Months Ended

Dec. 31, 2018

ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES

ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES

12. ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES


	As of December 31,
	2017	2018
	RMB	RMB
Accrued payroll and social insurance	28,536,755	32,008,825
Warranty—current	18,269,927	31,262,442
Sales rebate	14,317,285	34,029,433
Deposits	8,784,383	16,360,762
Deferred ADR income	—	4,250,126
Other taxes payable	1,099,932	3,656,732
IPO cost payable	—	3,130,639
Interest payable	167,269	318,774
Others*	4,237,318	9,166,293
Accrued Expenses and Other Current Liabilities	75,412,869	134,184,026

Others mainly include accrued professional fees and accrued marketing expenses.

The Group provides limited warranty to its users for terms varying from six months to three years, subject to certain conditions, such as normal use. For the electric motor, the Group provides a 24‑month or 30,000‑kilometer warranty. For lithium-ion battery packs, the Group provides a 24‑month or 20,000‑kilometer warranty or a 36‑month or 30,000‑kilometer warranty, depending on the model.

For other parts of the Group’s smart electric-scooters, the Group provides quality warranty varying from six months to 24 months depending on the parts. The Group is responsible for replacing or repairing the faulty products during their respective warranty terms.

The Group provides for the estimated costs of warranties at the time revenue is recognized. Factors that affect the Group’s warranty obligation include product defect rates and costs of repair or replacement.

Movement of provision for warranty is as follows:


	For the Year ended December 31
	2016	2017	2018
Accrued warranty—beginning of year	7,688,887	17,649,411	30,648,678
Accrual for warranties issued during the year	15,315,474	27,395,169	29,346,974
Warranty claims paid	(5,354,950)	(14,395,902)	(7,923,760)
Pre-existing warranty expired	—	—	(3,199,608)
Accrued warranty—end of year	17,649,411	30,648,678	48,872,284

REDEEMABLE CONVERTIBLE PREFERRED SHARES

12 Months Ended

Dec. 31, 2018

REDEEMABLE CONVERTIBLE PREFERRED SHARES

REDEEMABLE CONVERTIBLE PREFERRED SHARES

13. REDEEMABLE CONVERTIBLE PREFERRED SHARES

On March 5, 2015, the Company issued convertible loan of US$3.9 million to GGV Capital V L.P., GGV Capital V Entrepreneurs Fund L.P., IDG China Venture Capital Fund IV L.P., and IDG China IV Investors L.P. in aggregate (the "2015 Convertible Loan"), which carried nil interest and was due by September 5, 2015. On May 27, 2015, the Company issued 16,666,667 Series A‑1 Preferred Shares at US$1.20 per share, of which 3,250,000 Series A‑1 Preferred Shares were issued upon conversion the 2015 Convertible Loan. The total proceeds from the issuance of Series A‑1 Preferred Shares was US$16,100,000 (equivalent to RMB101,208,371), of which US$9,500,000 (equivalent to RMB58,139,551) and US$6,600,000 (equivalent to RMB43,068,820) was received in the year ended December 31, 2015 and 2016, respectively.

On May 27, 2015, the Company issued 3,608,247 Series A‑2 redeemable convertible preferred shares ("Series A‑2 Preferred Shares") at US$1.66 per share. The total proceeds from the issuance of Series A‑2 Preferred Shares was US$6,000,000 (equivalent to RMB36,720,422).

On January 29, 2016, the Company issued 5,003,436 Series A‑3 Preferred Shares at US$2.08 per share. The total proceeds from the issuance of Series A‑3 Preferred Shares was US$10,400,000 (equivalent to RMB67,883,227).

On March 26, 2018, the holders of 2016 Convertible Loan converted the entire outstanding principal of the 2016 Convertible Loan of US$16,827,000 to 10,119,329 Series A-3 Preferred Shares at the conversion price of US$1.66 per share. The carrying amount of 2016 Convertible Loan of RMB181,112,874 as of March 26, 2018 was recorded as the initial amount reported in Series A-3 Preferred Shares.

On March 26, 2018, the Company issued 5,137,859 Series B redeemable convertible preferred shares ("Series B Preferred Shares") at the price of US$4.96 per share to Plum Angel Investment Co., Ltd., GGV Capital V L.P., GGV Capital V Entrepreneurs Fund L.P., GGV Capital Select L.P., Phoenix Wealth Investment (Holdings) Limited, Future Capital Discovery Fund I, L.P., IDG China Venture Capital Fund IV L.P. and IDG China IV Investors L.P. in aggregate. The total proceeds from the issuance of Series B Preferred Shares was US$25,500,000 (equivalent to RMB161,392,196).

The Company classified Series A‑1 Preferred Shares, Series A‑2 Preferred Shares, Series A‑3 Preferred Shares (collectively "Series A Preferred Shares"), and Series B Preferred Shares as mezzanine equity in the consolidated balance sheets since they are contingently redeemable at the option of the holders after a specified time period.

The Company evaluated the embedded conversion option in the Series A Preferred Shares and Series B Preferred Shares to determine if the embedded conversion option require bifurcation and accounting for as a derivative. The Company concluded the embedded conversion option did not need to be bifurcated pursuant to ASC 815 Derivatives and Hedging. The Company also determined that there was no beneficial conversion feature attributable to the Series A Preferred Shares and Series B Preferred Shares because the initial effective conversion prices of these shares were higher than the fair value of the Company’s ordinary shares at the relevant commitment dates. The fair value of the Company’s ordinary shares on the commitment date was estimated by management with the assistance of an independent valuation firm. The Company also determined there was no other embedded features to be separated from Series A Preferred Shares or Series B Preferred Shares.

The rights, preferences and privileges of the redeemable convertible preferred shares are as follows:

Redemption Rights

The redemption date of Series A Preferred Shares was at any time:

(i)

after the fifth-year anniversary of May 27, 2015, subject to the applicable laws of the Cayman Islands; or

(ii)

any holder of any other class of shares elects to exercise its redemption right.

The redemption date of Series B Preferred Shares was at any time:

(i)

after the fifth-year anniversary of March 26, 2018, subject to the applicable laws of the Cayman Islands; or

(ii)

any holder of any other class of shares elects to exercise its redemption right.

The Company shall redeem, up to all of the outstanding Series A Preferred Shares and Series B Preferred Shares out of funds legally available therefor including capital in accordance with the agreement, provided, however, that no Series A redemption price shall be paid until the Series B redemption price with respect to the Series B Preferred Shares requested to be redeemed is paid.

The redemption price for Series A Preferred Shares or Series B Preferred Shares, shall be the sum of their issue price, all accrued dividends, and any declared but unpaid dividends thereon up to the date of redemption.

Conversion Rights

Each redeemable convertible preferred share is convertible, at the option of the holder, at any time after the issuance date according to a conversion ratio, subject to adjustments for dilution, including but not limited to stock splits, stock dividends and certain other events. Each redeemable convertible preferred share is convertible into a number of ordinary shares determined by dividing the applicable original issuance price by the conversion price. The conversion price of each redeemable convertible preferred share is the same as its original issuance price and no adjustments to conversion price have occurred. As of December 31, 2017, each redeemable convertible preferred share is convertible into one ordinary share.

Each Series A Preferred Share shall automatically be converted into Ordinary Shares at a 1‑to‑1 initial conversion ratio immediately upon the closing of a Qualified Initial Public Offering ("Qualified IPO"), and approved by the holders of more than two-thirds of the Series A Preferred Shares. Each Series B Preferred Share shall automatically be converted into Ordinary Shares at a 1-to-1 initial conversion ratio immediately upon the closing of a Qualified IPO, and approved by the holders of more than half of the Series B Preferred Shares.

A "Qualified IPO" was defined as the closing of a firm commitment underwritten public offering of the Ordinary Shares (or depositary receipts or depositary shares therefor) in the United States pursuant to an effective registration statement under the United States Securities Act of 1933, as amended, with an offering price per share (net of underwriting commissions and expenses) that reflects the valuation of the Company immediately prior to such offering of at least US$1,000,000,000 and that results in gross proceeds to the Company of at least US$100,000,000, or in a public offering of the Ordinary Shares in the Hong Kong S.A.R. or any other jurisdiction which results in the Ordinary Shares trading publicly on a recognized international securities exchange so long as the offering price per share (net of underwriting commissions and expenses) satisfies the foregoing pre-offering valuation and gross proceeds requirements, in each case, unless such requirements are waived by the holders of more than two-thirds of the Series A Preferred Shares.

Voting Rights

Each redeemable convertible preferred share shall be entitled to that number of votes corresponding to the number of ordinary shares on an as-converted basis. Redeemable convertible preferred share shall vote separately as a class with respect to certain specified matters. Otherwise, the holders of redeemable convertible preferred shares, convertible preferred shares and ordinary shares shall vote together as a single class.

Dividend Rights

Prior to the issuance of Series B Preferred Shares in March 2018, each holder of Series A Preferred Shares shall be entitled to receive dividends payable only when, as and if declared by the majority of the Board, out of any assets at the time legally available therefor, in preference and priority to any declaration or payment of any dividends on Ordinary Shares, Series Seed convertible preferred shares ("Series Seed Preferred Shares") or any other class or series of shares issued by the Company, and shall participate in any subsequent distribution among the Ordinary Shares, Series Seed Preferred Shares and all other classes or series of shares issued by the Company pro rata based on the number of Ordinary Shares held by such holder of Series A Preferred Shares (calculated on an as-converted basis).

Upon the issuance of Series B Preferred Shares and amendment and restatement of Memorandum of Association thereupon in March 2018, each holder of a Series A Preferred Share shall be entitled to receive dividends payable only when, as and if declared by the majority of the Board, out of any assets at the time legally available therefor, in preference and priority to any declaration or payment of any dividends on Ordinary Shares, Series Seed Preferred Shares, or any other class or series of shares issued by the Company (other than Series B Preferred Shares), and shall participate in any subsequent distribution among the Ordinary Shares, Series Seed Preferred Shares and all other classes or series of shares issued by the Company pro rata based on the number of Ordinary Shares held by such holder of Series A Preferred Shares (calculated on an as-converted basis).

Liquidation Preferences

Prior to the issuance of Series B Preferred Shares in March 2018, in the event of any liquidation including deemed liquidation, dissolution or winding up of the Company, holders of the Series A Preferred Shares shall be entitled to receive a per share amount equal to 150% of the original preferred share issue price of the respective series of preferred shares, as adjusted for share dividends, share splits, combinations, recapitalizations or similar events, plus all accrued and declared but unpaid dividends thereon, in the following sequence: Series A Preferred Shares and Series Seed Preferred Shares. After such liquidation amounts have been paid in full, any remaining funds or assets of the Company legally available for distribution to shareholders shall be distributed on a pro rata, pari passu basis among the holders of the then outstanding preferred shares (on an as-converted basis), together with the holders of the then outstanding ordinary shares.

Upon the issuance of Series B Preferred Shares and amendment and restatement of Memorandum of Association thereupon in March 2018, in the event of any liquidation including deemed liquidation, dissolution or winding up of the Company, holders of the Series A and Series B Preferred Shares shall be entitled to receive a per share amount equal to 150% of the original preferred share issue price of the respective series of preferred shares, as adjusted for share dividends, share splits, combinations, recapitalizations or similar events, plus all accrued and declared but unpaid dividends thereon, in the following sequence: Series B Preferred Shares, Series A Preferred Shares and Series Seed Preferred Shares. After such liquidation amounts have been paid in full, any remaining funds or assets of the Company legally available for distribution to shareholders shall be distributed on a pro rata, pari passu basis among the holders of the then outstanding preferred shares (on an as-converted basis), together with the holders of the then outstanding ordinary shares.

With approval from the holders of Series A Preferred Shares and Series B Preferred Shares and waiver of the Qualified IPO from the holders of Series A Preferred Shares, all of the redeemable convertible preferred shares were converted to Class A ordinary shares immediately prior to the completion of the Company’s initial public offering on October 19, 2018.

The Company's redeemable convertible preferred shares activities consist of the following:


			Series A-2	Series A-3	Series B
			Preferred	Preferred	Preferred
	Series A-1 Preferred Shares		Shares	Shares	Shares
	Carrying	Subscription	Carrying	Carrying	Carrying
RMB	amount	receivable	amount	amount	amount	Total
Balance as of January 1, 2016	129,872,003	(42,857,760)	38,961,592	—	—	125,975,835
Issuance of preferred shares	—	—	—	67,883,227	—	67,883,227
Subscription receivable	—	43,068,820	—	—	—	43,068,820
Foreign currency translation adjustment	8,868,000	(211,060)	2,660,400	4,261,191	—	15,578,531
Balance as of December 31, 2016	138,740,003	—	41,621,992	72,144,418	—	252,506,413
Foreign currency translation adjustment	(8,056,000)	—	(2,416,800)	(4,189,098)	—	(14,661,898)
Balance as of December 31, 2017	130,684,003	—	39,205,192	67,955,320	—	237,844,515
Issuance of preferred shares	—	—	—	181,112,874	161,392,196	342,505,070
Foreign currency translation adjustment	8,090,000	—	2,427,000	21,651,035	15,544,654	47,712,689
Conversion to Ordinary Shares	(138,774,003)	—	(41,632,192)	(270,719,229)	(176,936,850)	(628,062,274)
Balance as of December 31, 2018	—	—	—	—	—	—

ORDINARY SHARES AND SERIES SEED PREFERRED SHARES	12 Months Ended
ORDINARY SHARES AND SERIES SEED PREFERRED SHARES	Dec. 31, 2018
ORDINARY SHARES AND SERIES SEED PREFERRED SHARES
ORDINARY SHARES AND SERIES SEED PREFERRED SHARES	14. ORDINARY SHARES AND SERIES SEED PREFERRED SHARES Ordinary Shares The Company’s Memorandum and Articles of Association authorizes the Company to issue 444,721,650 ordinary shares of US$0.0001 par value as of December 31, 2017. On March 26, 2018, the Company repurchased 432,000 ordinary shares from Niu Holding Inc. beneficially owned by Mr. Token Yilin Hu at total consideration of US$665,000 (equivalent to RMB4,202,335). Such shares were cancelled immediately upon repurchase. In October 2018, the Company completed its initial public offering (“the IPO”) of 14,000,000 newly issued Class A ordinary shares, at a public offering price of US$4.5 per share. The net proceeds after deducting underwriting commissions and discounts were US$58,590,000 (equivalent to RMB406,538,433). Immediately prior to the completion of the IPO, the Company’s authorized share capital was increased to US$500,000 divided into 5,000,000,000 shares comprising of (i) 4,900,000,000 Class A ordinary shares with a par value of US$0.0001 each, (ii) 50,000,000 Class B ordinary shares with a par value of US$0.0001 each and (iii) 50,000,000 shares with a par value of US$0.0001 each of such class or classes (however designated) as the board of directors may determine in accordance with the Company’s post-offering Memorandum and Articles of Association. Immediately prior to the completion of the IPO, all outstanding preferred shares, including (i) 30,000,000 Series Seed Preferred Shares with a par value of US$0.0001 each, (ii) 16,666,667 of Series A-1 Preferred Shares with a par value of US$0.0001 each, (iii) 3,608,247 of Series A-2 Preferred Shares with a par value of US$0.0001 each, (iv) 15,122,765 Series A-3 Preferred Shares with a par value of US$0.0001 each, and (v) 5,137,859 of Series B Preferred Shares with a par value of US$0.0001 each, were converted into Class A ordinary shares on a one-for-one bases. All outstanding ordinary shares were re-designated and re-classified as Class A ordinary shares on a one-for-one basis, except that 6,615,000 ordinary shares held by ELLY Holdings Limited and 14,027,020 ordinary shares held by Niu Holding Inc. were re-classified and re-designated as Class B ordinary shares on a one-for-one basis. Holders of Class A ordinary shares and Class B ordinary shares have the same rights except for voting and conversion rights. Each Class A ordinary share entitles the holder to one vote on all matters subject to vote at general meetings of the Company, and each Class B ordinary share entitles the holder to four votes on all matters subject to vote at general meetings of the Company. Each Class B ordinary share is convertible into one Class A ordinary share. Class A ordinary shares are not convertible into Class B ordinary shares under any circumstances. As of December 31, 2018, there were 128,032,038 and 20,642,020 Class A and Class B ordinary shares outstanding. Series Seed Preferred Shares The Company’s Memorandum and Articles of Association authorizes the Company to issue 30,000,000 Series Seed Preferred Shares of US$0.0001 par value as of December 31, 2017. Series Seed Preferred Shares are not redeemable and are convertible to ordinary shares at a one-for-one initial conversion ratio at the option of the holder at any time after the date of issuance. The liquidation preference of Series Seed Preferred Shares is preferable to ordinary shares but subordinated to redeemable convertible preferred shares as disclosed in Note 13. Voting rights and dividend rights of Series Seed Preferred Shares are as same as ordinary shares. Immediately prior to the completion of the IPO, all outstanding Series Seed Preferred Shares were converted into Class A ordinary shares on one-for-one bases.

SHARE-BASED COMPENSATION

12 Months Ended

Dec. 31, 2018

SHARE-BASED COMPENSATION

SHARE-BASED COMPENSATION

15. SHARE-BASED COMPENSATION

Restricted ordinary shares

In May 2015, Mr. Yi’nan Li, Mr. Token Yilin Hu, Ms. Yuqin Zhang and Niu Holding Inc. entered into an arrangement with other investors of the Company, whereby all of their 59,459,020 ordinary shares became restricted and subject to service vesting conditions. The restricted ordinary shares vest equally in four years from the date of imposition of the restriction , which will be accelerated in the event of the Company’s IPO. The restricted ordinary shares are subject to repurchase by the Company upon termination of Mr. Yi’nan Li, Mr. Token Yilin Hu and Ms. Yuqin Zhang’s service with the Group. The Company has the right, at its sole discretion, to repurchase restricted ordinary shares at its par value within 60 days after the termination. The restricted ordinary shares are not transferable prior to be vested. Other than the restriction on transfer and service vesting conditions, restricted ordinary shareholders have all other rights and privileges as ordinary shareholders. Compensation cost was measured for the restricted ordinary shares using the estimated fair value of the Company’s ordinary shares of US$0.53 per share at the date of imposition of the restriction in May 2015, and is amortized to consolidated statements of comprehensive loss on a straight-line basis over the vesting term of four years.

In February 2016, Ms. Yuqin Zhang resigned from the Group and the Company determined not to repurchase restricted ordinary shares held by Ms. Yuqin Zhang. As such, all restricted ordinary shares held by Ms. Yuqin Zhang vested immediately, compensation cost of RMB7,574,133 was recognized immediately when the service condition was waived.

On January 7, 2016, the shareholders of the Company approved a modification of 3,307,500 restricted ordinary shares owned Mr. Yi’nan Li, through Niu Holding Inc.. Such number of restricted ordinary shares vested immediately and became transferable. Unrecognized compensation cost of RMB9,803,035 of 3,307,500 shares was recognized upon modification. Mr. Yi’nan Li transferred 3,307,500 ordinary shares to ELLY Holdings Limited, an entity owned by Dr. Yan Li, the new Chief Operating Officer of the Company who became the Chief Executive Officer of the Company in December 2017. On January 7, 2016, the Company also issued 3,307,500 restricted ordinary shares to ELLY Holdings Limited at par value. As a result of these transactions, ELLY Holdings Limited collectively owns 6,615,000 restricted ordinary shares which vest annually in equal instalments over four years from January 7, 2016.

On January 7, 2016, the Company also issued 1,804,000 restricted ordinary shares to Smart Power Group Limited, an entity owned by Mingming Huang, a new member of Board of Directors of the Company. 25% of the restricted ordinary shares vested on May 27, 2016 and the remaining 75% of the restricted ordinary shares vest annually in equal instalments over the next three years.

On June 8, 2018, Mr. Yi'nan Li and Mr. Mingming Huang resigned from the Company and the Company determined not to repurchase 9,798,125 and 451,000 restricted ordinary shares held by Mr. Yi'nan Li and Mr. Mingming Huang, respectively. It represented a modification to accelerate vesting. Compensation cost of RMB173,156,580 was recognized immediately as general and administrative expenses upon the modification.

On October 19, 2018, the remaining restricted ordinary shares of Mr. Token Yilin Hu and Dr. Yan Li were vested immediately upon the Company’s initial public offering. Compensation cost of RMB8,935,076 and RMB10,535,229 was immediately recognized as research and development expenses and general and administrative expenses, respectively.

A summary of the restricted ordinary shares activities for the year ended December 31, 2018 is presented below:


		Weighted
		average grant
	Number of	date fair
	shares	value
		US$
Outstanding at January 1, 2018	32,689,010	0.57
Granted	—	—
Vested	(32,689,010)	0.57
Outstanding at December 31, 2018	—	—

The total fair value of shares vested during the years ended December 31, 2016, 2017 and 2018 was RMB73,692,770, RMB58,848,966 and RMB264,075,922, respectively. Total compensation expenses recognized for restricted ordinary shares for the years ended December 31, 2016, 2017 and 2018 were allocated to the following expense items:


	For the year ended
	December 31,
	2016	2017	2018
	RMB	RMB	RMB
Research and development expenses	12,821,215	13,045,853	18,371,203
General and administrative expenses	62,763,591	46,185,090	207,871,076
Total restricted ordinary shares compensation expense	75,584,806	59,230,943	226,242,279

As of December 31, 2018, there's no unrecognized compensation expense related to restricted ordinary shares.

Transfer of ordinary shares

On June 8, 2018, Mr. Token Yilin Hu transferred 2,000,000 ordinary shares beneficially owned through Niu Holdings Inc. to Mr. Carl Chuankai Liu, the vice president of design of the Company at nil consideration. The Company accounted for such transfer as share-based compensation as the ordinary shares were granted to Mr. Carl Chuankai Liu as compensation for his services provided to the Group. As there was no service condition, RMB33,537,572 share-based compensation expenses were recognized in research and development expenses immediately upon transfer.

Share options and restricted share units

2016 Global Incentive Plan

In January 2016, the Company's Shareholders and Board of Directors approved 2016 Global Share Incentive Plan and amended it in March 2018 (the "Amended 2016 Plan"). Under the Amended 2016 Plan, a maximum aggregate number of 5,861,480 ordinary shares may be issued pursuant to all awards granted. Share options expire 10 years from the grant date.

Under the 2016 Plan, the Company has granted: (i) 4,776,250 share options with exercise price of US$0.20 per share and vesting schedule of 40% vesting on the second anniversary of the grant date and the remaining vesting in three equal annual installments; and (ii) 705,196 share options with exercise price of nil and vesting in four equal annual installments.

A summary of the share options activities for the year ended December 31, 2018 is presented below:


			Weighted
		Weighted	remaining
	Number of	average exercise	contractual	Aggregate
	shares	price	years	intrinsic value
		US$		US$
Outstanding at January 1, 2018	4,265,750	0.20
Granted	1,215,696	0.08
Forfeited	(167,200)	0.20
Outstanding at December 31, 2018	5,314,246	0.17	8.06	17,644,761
Exercisable as of December 31, 2018	2,059,200	0.20	7.24	6,795,360

The fair value of the options granted is estimated on the dates of grant using the binomial option pricing model with the following key assumptions used:


Grant Date:	2016	2017	2018
Risk-free rate of return (per annum)	1.52% - 1.95%	2.25% - 2.48%	2.78%-3.13%
Volatility	54.8% - 56.5%	51.7% - 54.4%	49.9%-50.9%
Expected dividend yield	0%	0%	0%
Exercise multiple	2.2	2.2	2.2
Fair value of underlying ordinary share	US$0.44 - US$0.80	US$0.44 - US$1.22	US$2.05 - US$4.10
Expected term (in years)	10	10	10

The expected volatility was estimated based on the historical volatility of comparable peer public companies with a time horizon close to the expected term of the Company’s options. The risk-free interest rate was estimated based on the yield to maturity of U.S. treasury bonds denominated in USD for a term consistent with the expected term of the Company’s options in effect at the option valuation date. The expected exercise multiple was estimated as the average ratio of the stock price to the exercise price of when employees would decide to voluntarily exercise their vested options. As the Company did not have sufficient information of past employee exercise history, it has considered the statistics on exercise patterns of employees compiled by Huddart and Lang in Huddart, S., and M. Lang. 1996. "Employee Stock Option Exercises: An Empirical Analysis." Journal of Accounting and Economics, vol. 21, no. 1 (February):5‑43, which are widely adopted by valuers as authoritative guidance on expected exercise multiples. Expected dividend yield is zero as the Company has never declared or paid any cash dividends on its shares, and the Company does not anticipate any dividend payments in the foreseeable future. Expected term is the contract life of the option.

The weighted average grant date fair value of the share options granted for the years ended December 31, 2016, 2017 and 2018 was US$0.56, US$0.86 and US$2.11, respectively. Compensation expenses recognized for share options for the years ended December 31, 2016, 2017 and 2018 were allocated to the following expense items:


	For the year ended
	December 31,
	2016	2017	2018
	RMB	RMB	RMB
Cost of revenues	220,226	253,545	246,947
Selling and marketing expenses	1,377,422	1,611,160	2,124,728
Research and development expenses	708,847	832,782	955,538
General and administrative expenses	413,602	598,668	2,392,740
Total share option compensation expense	2,720,097	3,296,155	5,719,953

As of December 31, 2018, RMB21,953,326 of total unrecognized compensation expense related to share options is expected to be recognized over a weighted average period of approximately 3.33 years.

In October 2018, the Company granted 100,000 restricted share units to five independent directors in aggregate. Restricted share units are generally granted with 50% vesting on the first anniversary of the grant date and the remaining vesting on the second anniversary.

A summary of the restricted ordinary units activities for the year ended December 31, 2018 is presented below:


		Weighted
		average grant
	Number of	date fair
	shares	value
		US$
Outstanding at January 1, 2018	—	—
Granted	100,000	4.33
Vested	—	—
Outstanding at December 31, 2018	100,000	4.33

Compensation cost recognized for restricted share units for the year ended December 31, 2018 was RMB375,123 and was recognized as general and administrative expenses. As of December 31, 2018, RMB2,597,292 of total unrecognized compensation expenses related to restricted share units are expected to be recognized over a weighted average period of approximately 1.75 years.

2018 Share Incentive Plan

In September 2018, the Company's Shareholders and Board of Directors approved the 2018 Share Incentive Plan (the "2018 Plan"). Under the 2018 Plan, the maximum aggregate number of ordinary shares available for issuance is 6,733,703 ordinary shares, which shall be increased by a number equal to 1.5% of the total number of ordinary shares issued and outstanding on the last day of the immediately preceding fiscal year, each fiscal year during the term of the 2018 Plan, if determined and approved by the board of directors for the relevant fiscal year. As of December 31, 2018, no share incentive award has been granted under the 2018 Plan.

Total share-based compensation expenses recognized for the years ended December 31, 2016, 2017 and 2018 were allocated to the following expense items:


	For the year ended December 31,
	2016	2017	2018
	RMB	RMB	RMB
Cost of revenues	220,226	253,545	246,947
Selling and marketing expenses	1,377,422	1,611,160	2,124,728
Research and development expenses	13,530,062	13,878,635	52,864,313
General and administrative expenses	63,177,193	46,783,758	210,638,939
Total share-based compensation expense	78,304,903	62,527,098	265,874,927

FAIR VALUE MEASUREMENT

12 Months Ended

Dec. 31, 2018

FAIR VALUE MEASUREMENT

FAIR VALUE MEASUREMENT

16. FAIR VALUE MEASUREMENT

The following tables present the fair value hierarchy for those assets and liabilities measured at fair value on a recurring basis at December 31, 2017 and 2018, respectively:


	December 31, 2018			Total
RMB	Level 1	Level 2	Level 3	Fair Value
Assets
Short-term investments (Note 3)	—	120,241,425	—	120,241,425


	December 31, 2017			Total
RMB	Level 1	Level 2	Level 3	Fair Value
Assets
Short-term investments (Note 3)	—	85,187,718	—	85,187,718
Liabilities
Convertible loan (Note 11)	—	—	151,557,796	151,557,796

The table below reflects the reconciliation from the opening balances to the closing balances for a convertible loan, a recurring fair value measurement categorized as Level 3 of the fair value hierarchy, for the years ended December 31, 2016, 2017, and 2018, respectively:


	For the Year Ended December 31,
	2016	2017	2018
Convertible loan - beginning of year	—	116,728,899	151,557,796
Issuance	115,808,672	—	—
Change in fair value	—	43,006,399	34,499,858
Conversion to Series A-3 Preferred Shares	—	—	(181,112,874)
Foreign currency translation adjustment	920,227	(8,177,502)	(4,944,780)
Convertible loan - end of year	116,728,899	151,557,796	—

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

INCOME TAX

12 Months Ended

Dec. 31, 2018

INCOME TAX

INCOME TAX

17. INCOME TAX

a) Income tax

Cayman Islands

Under the current laws of the Cayman Islands, the Company is not subject to tax on income or capital gain. Additionally, the Cayman Islands does not impose a withholding tax on payments of dividends to shareholders.

No stamp duty is payable in respect of the issue of the shares or on an instrument of transfer in respect of a share.

Hong Kong

Under the current Hong Kong Inland Revenue Ordinance, the Company’s Hong Kong subsidiary is subject to Hong Kong profits tax at the rate of 16.5% on its taxable income generated from the operations in Hong Kong. Payments of dividends by the Hong Kong subsidiary to the Company is not subject to withholding tax in Hong Kong.

PRC

The Group’s PRC subsidiaries, the VIE, and VIE’s subsidiaries are subject to the PRC Corporate Income Tax Law ("CIT Law") and are taxed at the statutory income tax rate of 25%, unless otherwise specified.

The CIT Law also provides that an enterprise established under the laws of a foreign country or region but whose "de facto management body" is located in the PRC be treated as a resident enterprise for PRC tax purposes and consequently be subject to the PRC income tax at the rate of 25% for its global income. The Implementing Rules of the CIT Law define the location of the "de facto management body" as "the place where the exercising, in substance, of the overall management and control of the production and business operation, personnel, accounting, property, etc., of a non-PRC company is located." Based on a review of surrounding facts and circumstances, the Group does not believe that it is likely that its operations outside the PRC should be considered a resident enterprise for PRC tax purposes.

The components of (loss)/income before income taxes are as follows:


		For the Year Ended
		December 31,
	2016	2017	2018
	RMB	RMB	RMB
Cayman	(4,788,106)	(39,610,348)	(34,397,077)
Hong Kong SAR	(645,109)	219,935	(4,507,360)
PRC, excluding Hong Kong SAR	(227,287,707)	(145,272,458)	(310,123,039)
Total	(232,720,922)	(184,662,871)	(349,027,476)

The Group had no current income tax expense for the years ended December 31, 2016, 2017 and 2018, as the entities in the Group had no taxable income in the respective years.

Withholding tax on undistributed dividends

The CIT law also imposes a withholding income tax of 10% on dividends distributed by a foreign investment enterprise ("FIE") to its immediate holding company outside of China, if such immediate holding company is considered as a non-resident enterprise without any establishment or place within China or if the received dividends have no connection with the establishment or place of such immediate holding company within China, unless such immediate holding company’s jurisdiction of incorporation has a tax treaty with China that provides for a different withholding arrangement. The Cayman Islands, where the Company is incorporated, does not have such tax treaty with China. According to the arrangement between Mainland China and Hong Kong Special Administrative Region on the Avoidance of Double Taxation and Prevention of Fiscal Evasion in August 2006, dividends paid by an FIE in China to its immediate holding company in Hong Kong will be subject to withholding tax at a rate of no more than 5% (if the foreign investor owns directly at least 25% of the shares of the FIE). The Group did not record any dividend withholding tax, as the Group’s PRC entities, have no retained earnings in any of the periods presented.

Reconciliation of the differences between PRC statutory income tax rate and the Group’s effective income tax rate for the years ended December 31, 2016, 2017 and 2018 are as follows:


		For the Year Ended
		December 31,
	2016	2017	2018
	RMB	RMB	RMB
Computed expected income tax expense	(58,180,231)	(46,165,718)	(87,256,869)
Non-PRC entities not subject to income tax	1,358,304	9,847,603	9,726,109
Research and development expenses bonus deduction	(1,285,563)	(1,032,177)	(7,528,081)
Non-deductible share-based compensation expenses	19,576,226	15,631,775	66,374,951
Other non-deductible expenses	106,757	358,759	176,111
Change in valuation allowance	38,424,507	21,359,758	18,507,779
Actual income tax expense	—	—	—

b) Deferred income tax assets


	As of December 31,
	2017	2018
	RMB	RMB
Net operating loss carry forwards	63,106,433	74,657,570
Accrued warranty	7,662,170	12,218,071
Accrued payroll and social insurance	4,112,541	5,099,295
Deferred revenue	2,499,515	3,225,283
Advertising expense	1,834,909	2,955,152
Allowance for doubtful accounts	489,061	57,037
Less: Valuation allowance	(79,704,629)	(98,212,408)
Total deferred income tax assets	—	—

As of December 31, 2018, the Group had net operating loss carry forwards of RMB298,630,280 attributable to the PRC subsidiaries, the VIE, and VIE’s subsidiaries. Tax losses of RMB70,541,275, RMB125,990,557, RMB50,592,424 and RMB51,506,024 will expire, if unused, by 2020, 2021, 2022 and 2023, respectively.

A valuation allowance is provided against deferred income tax assets when the Group determines that it is more likely than not that the deferred income tax assets will not be utilized in the foreseeable future. In making such determination, the Group evaluates a variety of factors including the Group’s operating history, accumulated deficit, existence of taxable temporary differences and reversal periods.

The Group has incurred accumulated net operating losses for income tax purposes since its inception. The Group believes that it is more likely than not that these accumulated net operating losses and other deferred income tax assets will not be utilized in the foreseeable future. Accordingly, the Group has provided full valuation allowance for the deferred income tax assets as of December 31, 2017 and 2018.

Changes in valuation allowance are as follows:


		For the Year Ended
		December 31,
	2016	2017	2018
	RMB	RMB	RMB
Balance at the beginning of the year	19,920,364	58,344,871	79,704,629
Additions	38,424,507	21,359,758	18,507,779
Balance at the end of the year	58,344,871	79,704,629	98,212,408

According to the PRC Tax Administration and Collection Law, the statute of limitation is three years if the underpayment of taxes is due to computational errors made by the taxpayer or the withholding agent. The statute of limitation is extended to five years under special circumstances where the underpayment of taxes is more than RMB100,000. In the case of transfer pricing issues, the statute of limitation is 10 years. There is no statute of limitation in the case of tax evasion. The income tax returns of the Company’s PRC subsidiaries, consolidated VIE and VIE’s subsidiaries for the years from 2014 to 2018 are open to examination by the PRC tax authorities.

NET LOSS PER ORDINARY SHARE

12 Months Ended

Dec. 31, 2018

NET LOSS PER ORDINARY SHARE

NET LOSS PER ORDINARY SHARE

18. NET LOSS PER ORDINARY SHARE

The following table sets forth the basic and diluted net loss per share computation and provides a reconciliation of the numerator and denominator for the periods presented:


		For the Year Ended
		December 31,
	2016	2017	2018
	RMB	RMB	RMB
Numerator:
Net loss attributable to ordinary shareholders	(232,720,922)	(184,662,871)	(349,027,476)
Numerator for basic and diluted net loss per share calculation	(232,720,922)	(184,662,871)	(349,027,476)

Denominator:
Weighted average number of shares outstanding used in computing net loss per share	10,414,325	26,295,181	65,834,876

Denominator for basic and diluted net loss per share calculation	10,414,325	26,295,181	65,834,876

Net loss per share attributable to ordinary shareholders
—Basic and diluted	(22.35)	(7.02)	(5.30)

Securities that could potentially dilute basic net loss per share in the future that were not included in the computation of diluted net loss per share because to do so would have been antidilutive for the years ended December 31, 2017 and 2018 are as follow:


	For the Year Ended
	December 31,
	2017	2018
Share options	4,265,750	5,314,246
Restricted share units	—	100,000
Restricted ordinary shares	32,689,010	—
Series Seed Preferred Shares	30,000,000	—
Series A Preferred Shares	25,278,350	—
Convertible loan	10,119,329	—

REVENUE INFORMATION

12 Months Ended

Dec. 31, 2018

REVENUE INFORMATION

REVENUE INFORMATION

19. REVENUE INFORMATION

Net revenues consist of the following:


	For the Year Ended
	December 31,
	2016	2017	2018
	RMB	RMB	RMB
Electronic scooter sales	337,920,673	709,595,841	1,370,522,269
Accessory and Spare parts sales	14,920,309	49,159,080	91,373,179
Service revenues	1,969,066	10,613,080	15,885,856
Net revenues	354,810,048	769,368,001	1,477,781,304

The following summarizes the Group’s revenue from the following geographic areas (based on the location of customer):


	For the Year Ended
	December 31,
	2016	2017	2018
	RMB	RMB	RMB
PRC	353,041,492	731,423,647	1,318,657,227
Europe	1,118,230	36,257,165	148,963,330
Others	650,326	1,687,189	10,160,747
Net revenues	354,810,048	769,368,001	1,477,781,304

COMMITMENTS AND CONTINGENCIES

12 Months Ended

Dec. 31, 2018

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES

20. COMMITMENTS AND CONTINGENCIES

The Group leases its offices and facilities under non-cancelable operating lease agreements. Rental expenses were RMB3,981,515, RMB4,896,922 and RMB7,306,686 for the years ended December 31, 2016, 2017 and 2018, respectively.

As of December 31, 2018, future minimum lease commitments, all under office and facilities non-cancelable operating lease agreements, were as follows:


Year ending December 31,		RMB
2019		6,943,633
2020		3,333,014
2021		1,293,531

Except for those disclosed above, the Group did not have any significant capital or other commitments, long-term obligations, or guarantees as of December 31, 2017 and 2018.

PARENT COMPANY ONLY CONDENSED FINANCIAL INFORMATION

12 Months Ended

Dec. 31, 2018

PARENT COMPANY ONLY CONDENSED FINANCIAL INFORMATION

PARENT ONLY FINANCIAL INFORMATION

23. PARENT COMPANY ONLY CONDENSED FINANCIAL INFORMATION

For the presentation of the parent company only condensed financial information, the Company records its investment in subsidiaries, consolidated VIE and VIE’s subsidiaries, under the equity method of accounting as prescribed in ASC 323, “Investments-Equity Method and Joint Ventures”. Such investments are presented on the condensed balance sheets as “Investment in subsidiaries and consolidated VIE and VIE's subsidiaries” and the subsidiaries, consolidated VIE and VIE’s subsidiaries’ losses as “Share of losses from subsidiaries, VIE and VIE's subsidiaries” on the condensed statements of results of operations. The parent company only condensed financial information should be read in conjunction with the Company’s consolidated financial statements. As of December 31, 2018, there were no material contingencies, significant provisions of long-term obligations, mandatory dividend or redemption requirements of redeemable stocks or guarantees of Niu Technologies, except for those, which have been separately disclosed in the consolidated financial statements.

(a)

Condensed Balance Sheets


	As of December 31,
	2017	2018
	RMB	RMB
Assets
Current assets
Cash	39,678,102	149,901,311
Term deposit	—	27,452,663
Restricted cash—current	52,273,600	124,357,114
Amount due from subsidiaries and consolidated VIE and VIE's subsidiaries	53,490,993	405,843,735
Prepayments and other current assets	—	3,707,403
Total current assets	145,442,695	711,262,226
Non-current assets:
Investment in subsidiaries and consolidated VIE and VIE's subsidiaries	—	—
Restricted cash—non current	65,342,000	—
Total non-current assets	65,342,000	—
Total assets	210,784,695	711,262,226

Liabilities
Current liabilities
Convertible loan	151,557,796	—
Amount due to subsidiaries and consolidated VIE and VIE’s subsidiaries	—	4,262,270
Accrued expenses and other current liabilities	—	7,593,082
Total current liabilities and total liabilities	151,557,796	11,855,352
Mezzanine Equity
Series A-1 Redeemable Convertible Preferred Shares	130,684,003	—
Series A-2 Redeemable Convertible Preferred Shares	39,205,192	—
Series A-3 Redeemable Convertible Preferred Shares	67,955,320	—
Total mezzanine equity	237,844,515	—

Shareholders' (deficit)/equity:
Ordinary Shares	39,948	—
Class A Ordinary Shares	—	83,120
Class B Ordinary Shares	—	12,839
Series Seed Convertible Preferred Shares	18,436	—
Additional paid-in capital	440,265,896	1,717,483,548
Accumulated other comprehensive income/(loss)	3,281,862	(25,394,429)
Accumulated deficit	(622,223,758)	(992,778,204)
Total shareholders' (deficit)/equity	(178,617,616)	699,406,874
Total liabilities, mezzanine equity and shareholders' (deficit)/equity	210,784,695	711,262,226

(b)

Condensed Statements of Results of Operations


	For the Year Ended December 31,
	2016	2017	2018
	RMB	RMB	RMB
Total operating expenses	(393,856)	(163,640)	(1,908,246)
Changes in fair value of a convertible loan	—	(43,006,399)	(34,499,858)
Share of losses from subsidiaries, VIE and VIE's subsidiaries	(198,821,537)	(62,527,098)	(331,955,300)
Interest income	150,594	366,795	2,011,390
Foreign currency exchange (losses)/gain	(4,544,844)	3,192,896	(364)
Loss before income tax	(203,609,643)	(102,137,446)	(366,352,378)
Income tax expense	—	—	—
Net loss	(203,609,643)	(102,137,446)	(366,352,378)

(c)

Condensed statements of cash flows


	For the Year Ended
	December 31,
	2016	2017	2018
	RMB	RMB	RMB
Net cash (used in)/provided by operating activities	(76,650,478)	12,825,090	(352,222,011)
Net cash used in investing activities	—	—	(19,902,073)
Net cash provided by financing activities	104,354,252	—	481,123,035
Effect of foreign currency exchange rate changes on cash	(498,905)	(1,889,261)	1,224,258
Net increase in cash	27,204,869	10,935,829	110,223,209
Cash at the beginning of the year	1,537,404	28,742,273	39,678,102
Cash at the end of the year	28,742,273	39,678,102	149,901,311

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)

12 Months Ended

Dec. 31, 2018

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Basis of presentation

(a) Basis of presentation

The accompanying consolidated financial statements of the Group have been prepared in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP").

Principles of Consolidation

(b) Principles of Consolidation

All intercompany transactions and balances among the Company, its subsidiaries, the VIE, and the VIE’s subsidiaries have been eliminated upon consolidation.

Use of Estimates

Convenience Translation

(d) Convenience Translation

Commitments and Contingencies

(e) Commitments and Contingencies

Cash

(f) Cash


	As of December 31,
	2017	2018
	RMB	RMB
Financial institutions in the mainland of the PRC
—Denominated in RMB	51,157,225	145,529,365
—Denominated in USD	23,525,190	155,583,394
—Denominated in EUR	257	—
Total cash balances held at mainland PRC financial institutions	74,682,672	301,112,759

Financial institutions in the United States
—Denominated in USD	37,307,479	4,038,742
Total cash balances held at the United States financial institutions	37,307,479	4,038,742

Financial institutions in the Hong Kong S.A.R.
—Denominated in USD	—	263,588,286

Total cash balances held at the Hong Kong S.A.R. financial institutions	—	263,588,286
Total cash balances held at financial institutions	111,990,151	568,739,787

Term deposit

(g) Term deposit

Restricted Cash

(h) Restricted Cash

Short-term investments

(i) Short-term investments

Accounts Receivable

(j) Accounts Receivable

Inventories

(k) Inventories

Property and Equipment, net

(l) Property and Equipment, net

Property and equipment are stated at cost less accumulated depreciation and any recorded impairment.

The estimated useful lives are as follows:


Machinery and equipment		3 ~ 10 years
Furniture		3 years
Leasehold improvements		3 years
Office and electronic equipment		2 ~ 5 years
Motor vehicles		4 years

Depreciation on property and equipment is calculated on the straight-line method over the estimated useful lives of the assets.

Depreciation and amortization of property and equipment attributable to manufacturing activities is capitalized as part of inventories, and recognized as cost of revenues when the inventory is sold.

Intangible assets

(m) Intangible assets

Impairment of Long-lived Assets

(n) Impairment of Long-lived Assets

Value added taxes

(o) Value added taxes

Fair Value Measurements

(p) Fair Value Measurements

Level 1—Observable inputs that reflect quoted prices (unadjusted) for identical assets or liabilities in active markets.

Level 2—Include other inputs that are directly or indirectly observable in the marketplace.

Level 3—Unobservable inputs which are supported by little or no market activity.

The Group’s non-financial assets, such as intangible assets and property and equipment, would be measured at fair value only if they were determined to be impaired.

Revenue recognition

(q) Revenue recognition

For some sales, the Group collects cash before delivery. Cash collected before product delivery is recognized as advances from customers.

Warranties

(r) Warranties

Cost of Revenues

(s) Cost of Revenues

Cost of revenues mainly consists of the cost of products sold, write-downs of inventories, logistics costs and warranty costs.

Selling and Marketing Expenses

(t) Selling and Marketing Expenses

General and Administrative Expenses

(u) General and Administrative Expenses

Research and Development Expenses

(v) Research and Development Expenses

Government Grants

(w) Government Grants

Share-based Compensation

(x) Share-based Compensation

The Company periodically grants share-based awards, including but not limited to, restricted ordinary shares, restricted share units, and share options to eligible employees and directors.

Employee Benefits

(y) Employee Benefits

Income Taxes

(z) Income Taxes

Operating leases

(aa) Operating leases

Foreign currency translation and foreign currency risks

(bb) Foreign currency translation and foreign currency risks

Concentration and risk

(cc) Concentration and risk

Concentration of customers and suppliers

No customers individually represent greater than 10% of total net revenues of the Group for the years ended December 31, 2016, 2017 and 2018.

Suppliers from whom individually represent greater than 10% of total purchases of the Group for the years ended December 31, 2016, 2017 and 2018, are as follows:


	For the Year ended December 31,
	2016			2017			2018
	RMB	%		RMB	%		RMB	%
Supplier F	*	*		*	*		193,555,999	15	%
Supplier A	51,368,000	12	%	187,065,077	21	%	150,385,652	12	%
Supplier B	61,900,615	14	%	152,966,930	18	%	*	*
Supplier C	60,072,473	14	%	*	*		*	*

Customers accounting for 10% or more of accounts receivable, net are as follows:


	As of December 31,
	2017			2018
	RMB	%		RMB	%
Customer Y	3,904,087	32	%	45,980,177	84	%
Customer Z	1,471,144	12	%	*	*

Customers accounting for 10% or more of advances from customers are as follows:


	As of December 31,
	2017			2018
	RMB	%		RMB	%
Customer V	9,021,739	19	%	*	*

Suppliers accounting for 10% or more of accounts payable are as follows:


	As of December 31,
	2017			2018
	RMB	%		RMB	%
Supplier E	*	*		26,483,893	11	%
Supplier F	*	*		25,702,037	10	%
Supplier B	17,048,400	14	%	*	*
Supplier D	12,623,108	10	%	*	*

The amount was less than 10% of total balance.

Concentration of credit risk

Financial instruments that potentially expose the Group to concentrations of credit risk consist principally of cash, term deposits, restricted cash, short-term investments and accounts receivable.

Interest rate risk

The Group’s short-term bank borrowing bears interests at fixed rates. If the Group were to renew these loans, the Group might be subject to interest rate risk.

Earnings/(Loss) per Share

(dd) Earnings/(Loss) per Share

Segment Reporting

(ee) Segment Reporting

Statutory Reserves

(ff) Statutory Reserves

Recent Accounting Pronouncements

(gg) Recent Accounting Pronouncements

DESCRIPTION OF ORGANIZATION AND PRINCIPAL ACTIVITIES (Tables)

12 Months Ended

Dec. 31, 2018

DESCRIPTION OF ORGANIZATION AND PRINCIPAL ACTIVITIES

Schedule of Group's VIE information


	As of December 31,
	2017	2018
	RMB	RMB
Cash	71,792,874	90,723,253
Short-term investments	85,187,718	120,241,425
Accounts receivable, net	10,382,112	54,424,845
Inventories	88,225,965	142,155,411
Prepayments and other current assets	7,349,583	22,711,514
Amounts due from related parties*	—	4,262,270
Total current assets	262,938,252	434,518,718

Property and equipment, net	28,696,602	40,580,352
Intangible assets, net	1,277,467	580,667
Other non-current assets	626,605	16,805,475
Total assets	293,538,926	492,485,212

Short-term bank borrowings	168,234,207	179,978,003
Accounts payable	124,937,465	249,665,890
Amounts due to related parties**	144,169,442	211,250,230
Advances from customers	48,503,389	20,505,861
Deferred revenue—current	9,853,361	12,666,330
Accrued expenses and other current liabilities	75,382,869	119,242,975
Total current liabilities	571,080,733	793,309,289

Warranty—non current	12,378,751	17,609,842
Deferred revenue—non current	144,700	234,801
Total liabilities	583,604,184	811,153,932

 Amounts due from related parties refers to the amounts due from the Company and Niudian Information which are eliminated upon consolidation.

 Amounts due to related parties refers to the amounts due to the Company and Niudian Information which are eliminated upon consolidation.


	For the Year Ended December 31,
	2016	2017	2018
	RMB	RMB	RMB
Net revenues	354,810,048	769,368,001	1,477,593,628
Net loss	(227,081,999)	(145,154,084)	(294,156,973)
Net cash (used in)/provided by operating activities	(80,026,685)	(2,423,156)	14,379,166
Net cash used in investing activities	(59,949,934)	(55,928,949)	(74,333,070)
Net cash provided by financing activities	185,610,980	68,703,310	78,199,492
Effect of foreign currency exchange rate changes on cash	196,441	(813,270)	684,791
Net increase in cash	45,830,802	9,537,935	18,930,379
Cash at the beginning of the year	16,424,137	62,254,939	71,792,874
Cash at the end of the year	62,254,939	71,792,874	90,723,253

- Definition

Tabular disclosure of the significant judgments and assumptions made in determining whether a variable interest (as defined) held by the entity requires the variable interest entity (VIE) (as defined) to be consolidated and (or) disclose information about its involvement with the VIE, individually or in aggregate (as applicable); the nature of restrictions, if any, on the consolidated VIE's assets and on the settlement of its liabilities reported by an entity in its statement of financial position, including the carrying amounts of such assets and liabilities; the nature of, and changes in, the risks associated with involvement in the VIE; how involvement with the VIE affects the entity's financial position, financial performance, and cash flows; the lack of recourse if creditors (or beneficial interest holders) of the consolidated VIE have no recourse to the general credit of the primary beneficiary (if applicable); the terms of arrangements, giving consideration to both explicit arrangements and implicit variable interests, if any, that could require the entity to provide financial support to the VIE, including events or circumstances that could expose the entity to a loss; the methodology used by the entity for determining whether or not it is the primary beneficiary of the variable interest entity; the significant factors considered and judgments made in determining that the power to direct the activities of a VIE that most significantly impact the VIE's economic performance are shared (as defined); the carrying amounts and classification of assets and liabilities of the VIE included in the statement of financial position; the entity's maximum exposure to loss, if any, as a result of its involvement with the VIE, including how the maximum exposure is determined and significant sources of the entity's exposure to the VIE; a comparison of the carrying amounts of the assets and liabilities and the entity's maximum exposure to loss; information about any liquidity arrangements, guarantees, and (or) other commitments by third parties that may affect the fair value or risk of the entity's variable interest in the VIE; whether or not the entity has provided financial support or other support (explicitly or implicitly) to the VIE that it was not previously contractually required to provide or whether the entity intends to provide that support, including the type and amount of the support and the primary reasons for providing the support; and supplemental information the entity determines necessary to provide.

+ References + Details

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)

12 Months Ended

Dec. 31, 2018

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Schedule of cash at bank and term deposits are deposited in financial institutions


	As of December 31,
	2017	2018
	RMB	RMB
Financial institutions in the mainland of the PRC
—Denominated in RMB	51,157,225	145,529,365
—Denominated in USD	23,525,190	155,583,394
—Denominated in EUR	257	—
Total cash balances held at mainland PRC financial institutions	74,682,672	301,112,759

Financial institutions in the United States
—Denominated in USD	37,307,479	4,038,742
Total cash balances held at the United States financial institutions	37,307,479	4,038,742

Financial institutions in the Hong Kong S.A.R.
—Denominated in USD	—	263,588,286

Total cash balances held at the Hong Kong S.A.R. financial institutions	—	263,588,286
Total cash balances held at financial institutions	111,990,151	568,739,787

Schedule of estimated useful lives of property and equipment


Machinery and equipment		3 ~ 10 years
Furniture		3 years
Leasehold improvements		3 years
Office and electronic equipment		2 ~ 5 years
Motor vehicles		4 years

Schedule of concentration of customers and suppliers


	For the Year ended December 31,
	2016			2017			2018
	RMB	%		RMB	%		RMB	%
Supplier F	*	*		*	*		193,555,999	15	%
Supplier A	51,368,000	12	%	187,065,077	21	%	150,385,652	12	%
Supplier B	61,900,615	14	%	152,966,930	18	%	*	*
Supplier C	60,072,473	14	%	*	*		*	*

Customers accounting for 10% or more of accounts receivable, net are as follows:


	As of December 31,
	2017			2018
	RMB	%		RMB	%
Customer Y	3,904,087	32	%	45,980,177	84	%
Customer Z	1,471,144	12	%	*	*

Customers accounting for 10% or more of advances from customers are as follows:


	As of December 31,
	2017			2018
	RMB	%		RMB	%
Customer V	9,021,739	19	%	*	*

Suppliers accounting for 10% or more of accounts payable are as follows:


	As of December 31,
	2017			2018
	RMB	%		RMB	%
Supplier E	*	*		26,483,893	11	%
Supplier F	*	*		25,702,037	10	%
Supplier B	17,048,400	14	%	*	*
Supplier D	12,623,108	10	%	*	*

The amount was less than 10% of total balance.

SHORT-TERM INVESTMENTS (Tables)

12 Months Ended

Dec. 31, 2018

SHORT-TERM INVESTMENTS

Schedule of short-term investments


	As of December 31,
	2017	2018
	RMB	RMB
Aggregate cost basis	85,000,000	120,000,000
Gross unrealized holding gain	187,718	241,425
Aggregate fair value	85,187,718	120,241,425

ACCOUNTS RECEIVABLES, NET (Tables)

12 Months Ended

Dec. 31, 2018

ACCOUNTS RECEIVABLES, NET

Schedule of accounts receivables, net


	As of December 31,
	2017	2018
	RMB	RMB
Accounts receivable	12,338,357	54,652,991
Allowance for doubtful accounts	(1,956,245)	(228,146)
Accounts Receivable, net	10,382,112	54,424,845

Schedule of movement of the allowance for doubtful accounts


	For the Year Ended
	December 31,
	2016	2017	2018
	RMB	RMB	RMB
Balance at the beginning of the year	—	47,846	1,956,245
Additions/(reversals) charged to bad debt expense	47,846	1,908,399	(1,215,464)
Write-off of bad debt allowance	—	—	(512,635)
Balance at the end of the year	47,846	1,956,245	228,146

INVENTORIES (Tables)

12 Months Ended

Dec. 31, 2018

INVENTORIES

Schedule of inventories


	As of December 31,
	2017	2018
	RMB	RMB
Raw materials	72,473,857	120,290,456
Works in progress	1,522,033	1,948,838
Finished goods	14,230,075	20,142,911
Inventories	88,225,965	142,382,205

PREPAYMENTS AND OTHER CURRENT ASSETS (Tables)

12 Months Ended

Dec. 31, 2018

PREPAYMENTS AND OTHER CURRENT ASSETS

Schedule of prepayments and other current assets


	As of December 31,
	2017	2018
	RMB	RMB
Advances to suppliers	2,772,494	15,507,866
Deductible input VAT and VAT rebates receivable	3,469,724	7,855,998
Staff advances	1,029,409	447,791
Others*	77,956	3,108,299
Prepayments and Other Current Assets	7,349,583	26,919,954

Others mainly include prepaid custom duties and interest income receivables.

PROPERTY AND EQUIPMENT, NET (Tables)

12 Months Ended

Dec. 31, 2018

PROPERTY AND EQUIPMENT, NET

Schedule of property and equipment


	As of December 31,
	2017	2018
	RMB	RMB
Machinery and equipment	17,453,885	22,615,657
Furniture	15,499,944	36,630,720
Office and electronic equipment	7,253,743	9,071,471
Leasehold improvement	1,897,392	2,116,266
Motor vehicles	454,647	802,251
Property and Equipment	42,559,611	71,236,365
Less: Accumulated depreciation	(13,863,009)	(30,251,191)
Property and Equipment, net	28,696,602	40,985,174

Schedule of depreciation expense on property and equipment allocated to expense items


	For the Year ended December 31,
	2016	2017	2018
	RMB	RMB	RMB
Cost of revenues	2,405,046	4,217,126	4,638,662
General and administrative expenses	1,120,533	1,873,711	2,261,620
Selling and marketing expenses	264,665	2,646,204	9,438,501
Research and development expenses	700,728	312,728	470,204
Total depreciation expense	4,490,972	9,049,769	16,808,987

INTANGIBLE ASSETS, NET (Tables)

12 Months Ended

Dec. 31, 2018

INTANGIBLE ASSETS, NET

Schedule of intangible assets


	As of December 31, 2017
		Gross		Net
	Amortization	carrying	Accumulated	carrying
RMB	period	amount	amortization	amount
Domain name	5 years	3,484,000	(2,206,533)	1,277,467


	As of December 31, 2018
		Gross		Net
	Amortization	carrying	Accumulated	carrying
RMB	period	amount	amortization	amount
Trademarks	5 years	8,564,505	(1,427,418)	7,137,087
Domain name	5 years	3,484,000	(2,903,333)	580,667
Total		12,048,505	(4,330,751)	7,717,754

OTHER NON-CURRENT ASSETS (Tables)

12 Months Ended

Dec. 31, 2018

OTHER NON-CURRENT ASSETS

Schedule of other non-current assets


	As of December 31,
	2017	2018
	RMB	RMB
Prepayments for land use right	—	12,329,652
Others*	626,605	4,475,822

Other non-current assets	626,605	16,805,474

Others mainly include prepayments for equipment and intangible assets.

SHORT-TERM BANK BORROWINGS AND RESTRICTED CASH (Tables)

12 Months Ended

Dec. 31, 2018

SHORT-TERM BANK BORROWINGS AND RESTRICTED CASH

Schedule of short-term bank borrowings


	As of December 31,
	2017	2018
	RMB	RMB
East West Bank loan	98,234,207	99,978,003
Bank of China loan	10,000,000	20,000,000
SPD Silicon Valley Bank loan	60,000,000	60,000,000
Short-term bank borrowings	168,234,207	179,978,003

ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES (Tables)

12 Months Ended

Dec. 31, 2018

ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES

Schedule of accrued expenses and other current liabilities


	As of December 31,
	2017	2018
	RMB	RMB
Accrued payroll and social insurance	28,536,755	32,008,825
Warranty—current	18,269,927	31,262,442
Sales rebate	14,317,285	34,029,433
Deposits	8,784,383	16,360,762
Deferred ADR income	—	4,250,126
Other taxes payable	1,099,932	3,656,732
IPO cost payable	—	3,130,639
Interest payable	167,269	318,774
Others*	4,237,318	9,166,293
Accrued Expenses and Other Current Liabilities	75,412,869	134,184,026

Others mainly include accrued professional fees and accrued marketing expenses.

Schedule of movement of provision for warranty


	For the Year ended December 31
	2016	2017	2018
Accrued warranty—beginning of year	7,688,887	17,649,411	30,648,678
Accrual for warranties issued during the year	15,315,474	27,395,169	29,346,974
Warranty claims paid	(5,354,950)	(14,395,902)	(7,923,760)
Pre-existing warranty expired	—	—	(3,199,608)
Accrued warranty—end of year	17,649,411	30,648,678	48,872,284

REDEEMABLE CONVERTIBLE PREFERRED SHARES (Tables)

12 Months Ended

Dec. 31, 2018

REDEEMABLE CONVERTIBLE PREFERRED SHARES

Schedule of redeemable convertible preferred shares activities


			Series A-2	Series A-3	Series B
			Preferred	Preferred	Preferred
	Series A-1 Preferred Shares		Shares	Shares	Shares
	Carrying	Subscription	Carrying	Carrying	Carrying
RMB	amount	receivable	amount	amount	amount	Total
Balance as of January 1, 2016	129,872,003	(42,857,760)	38,961,592	—	—	125,975,835
Issuance of preferred shares	—	—	—	67,883,227	—	67,883,227
Subscription receivable	—	43,068,820	—	—	—	43,068,820
Foreign currency translation adjustment	8,868,000	(211,060)	2,660,400	4,261,191	—	15,578,531
Balance as of December 31, 2016	138,740,003	—	41,621,992	72,144,418	—	252,506,413
Foreign currency translation adjustment	(8,056,000)	—	(2,416,800)	(4,189,098)	—	(14,661,898)
Balance as of December 31, 2017	130,684,003	—	39,205,192	67,955,320	—	237,844,515
Issuance of preferred shares	—	—	—	181,112,874	161,392,196	342,505,070
Foreign currency translation adjustment	8,090,000	—	2,427,000	21,651,035	15,544,654	47,712,689
Conversion to Ordinary Shares	(138,774,003)	—	(41,632,192)	(270,719,229)	(176,936,850)	(628,062,274)
Balance as of December 31, 2018	—	—	—	—	—	—

SHARE-BASED COMPENSATION (Tables)

12 Months Ended

Dec. 31, 2018

Restricted ordinary shares

SHARE-BASED COMPENSATION

Summary of the restricted ordinary shares activities


		Weighted
		average grant
	Number of	date fair
	shares	value
		US$
Outstanding at January 1, 2018	32,689,010	0.57
Granted	—	—
Vested	(32,689,010)	0.57
Outstanding at December 31, 2018	—	—

Schedule of share-based compensation expenses recognized


	For the year ended
	December 31,
	2016	2017	2018
	RMB	RMB	RMB
Research and development expenses	12,821,215	13,045,853	18,371,203
General and administrative expenses	62,763,591	46,185,090	207,871,076
Total restricted ordinary shares compensation expense	75,584,806	59,230,943	226,242,279

Amended 2016 Plan

SHARE-BASED COMPENSATION

Summary of the share options activities


			Weighted
		Weighted	remaining
	Number of	average exercise	contractual	Aggregate
	shares	price	years	intrinsic value
		US$		US$
Outstanding at January 1, 2018	4,265,750	0.20
Granted	1,215,696	0.08
Forfeited	(167,200)	0.20
Outstanding at December 31, 2018	5,314,246	0.17	8.06	17,644,761
Exercisable as of December 31, 2018	2,059,200	0.20	7.24	6,795,360

Schedule of stock option valuation allowance using the binomial option pricing model


Grant Date:	2016	2017	2018
Risk-free rate of return (per annum)	1.52% - 1.95%	2.25% - 2.48%	2.78%-3.13%
Volatility	54.8% - 56.5%	51.7% - 54.4%	49.9%-50.9%
Expected dividend yield	0%	0%	0%
Exercise multiple	2.2	2.2	2.2
Fair value of underlying ordinary share	US$0.44 - US$0.80	US$0.44 - US$1.22	US$2.05 - US$4.10
Expected term (in years)	10	10	10

Schedule of share-based compensation expenses recognized


	For the year ended
	December 31,
	2016	2017	2018
	RMB	RMB	RMB
Cost of revenues	220,226	253,545	246,947
Selling and marketing expenses	1,377,422	1,611,160	2,124,728
Research and development expenses	708,847	832,782	955,538
General and administrative expenses	413,602	598,668	2,392,740
Total share option compensation expense	2,720,097	3,296,155	5,719,953

Amended 2016 Plan | Restricted ordinary shares

SHARE-BASED COMPENSATION

Summary of the restricted ordinary shares activities


		Weighted
		average grant
	Number of	date fair
	shares	value
		US$
Outstanding at January 1, 2018	—	—
Granted	100,000	4.33
Vested	—	—
Outstanding at December 31, 2018	100,000	4.33

2018 Plan

SHARE-BASED COMPENSATION

Schedule of share-based compensation expenses recognized


	For the year ended December 31,
	2016	2017	2018
	RMB	RMB	RMB
Cost of revenues	220,226	253,545	246,947
Selling and marketing expenses	1,377,422	1,611,160	2,124,728
Research and development expenses	13,530,062	13,878,635	52,864,313
General and administrative expenses	63,177,193	46,783,758	210,638,939
Total share-based compensation expense	78,304,903	62,527,098	265,874,927

FAIR VALUE MEASUREMENT (Tables)

12 Months Ended

Dec. 31, 2018

FAIR VALUE MEASUREMENT

Schedule of fair value hierarchy for assets and liabilities measured at fair value on recurring basis


	December 31, 2018			Total
RMB	Level 1	Level 2	Level 3	Fair Value
Assets
Short-term investments (Note 3)	—	120,241,425	—	120,241,425


	December 31, 2017			Total
RMB	Level 1	Level 2	Level 3	Fair Value
Assets
Short-term investments (Note 3)	—	85,187,718	—	85,187,718
Liabilities
Convertible loan (Note 11)	—	—	151,557,796	151,557,796

Schedule of reconciliation of recurring fair value measurements categorized as Level 3


	For the Year Ended December 31,
	2016	2017	2018
Convertible loan - beginning of year	—	116,728,899	151,557,796
Issuance	115,808,672	—	—
Change in fair value	—	43,006,399	34,499,858
Conversion to Series A-3 Preferred Shares	—	—	(181,112,874)
Foreign currency translation adjustment	920,227	(8,177,502)	(4,944,780)
Convertible loan - end of year	116,728,899	151,557,796	—

INCOME TAX (Tables)

12 Months Ended

Dec. 31, 2018

INCOME TAX

Components of (loss)/income before income taxes


		For the Year Ended
		December 31,
	2016	2017	2018
	RMB	RMB	RMB
Cayman	(4,788,106)	(39,610,348)	(34,397,077)
Hong Kong SAR	(645,109)	219,935	(4,507,360)
PRC, excluding Hong Kong SAR	(227,287,707)	(145,272,458)	(310,123,039)
Total	(232,720,922)	(184,662,871)	(349,027,476)

Schedule of reconciliation of statutory income tax rate and effective income tax rate


		For the Year Ended
		December 31,
	2016	2017	2018
	RMB	RMB	RMB
Computed expected income tax expense	(58,180,231)	(46,165,718)	(87,256,869)
Non-PRC entities not subject to income tax	1,358,304	9,847,603	9,726,109
Research and development expenses bonus deduction	(1,285,563)	(1,032,177)	(7,528,081)
Non-deductible share-based compensation expenses	19,576,226	15,631,775	66,374,951
Other non-deductible expenses	106,757	358,759	176,111
Change in valuation allowance	38,424,507	21,359,758	18,507,779
Actual income tax expense	—	—	—

Schedule of deferred income tax assets


	As of December 31,
	2017	2018
	RMB	RMB
Net operating loss carry forwards	63,106,433	74,657,570
Accrued warranty	7,662,170	12,218,071
Accrued payroll and social insurance	4,112,541	5,099,295
Deferred revenue	2,499,515	3,225,283
Advertising expense	1,834,909	2,955,152
Allowance for doubtful accounts	489,061	57,037
Less: Valuation allowance	(79,704,629)	(98,212,408)
Total deferred income tax assets	—	—

Schedule of changes in valuation allowance


		For the Year Ended
		December 31,
	2016	2017	2018
	RMB	RMB	RMB
Balance at the beginning of the year	19,920,364	58,344,871	79,704,629
Additions	38,424,507	21,359,758	18,507,779
Balance at the end of the year	58,344,871	79,704,629	98,212,408

NET LOSS PER ORDINARY SHARE (Tables)

12 Months Ended

Dec. 31, 2018

NET LOSS PER ORDINARY SHARE

Schedule of basic and diluted net loss per share computation


		For the Year Ended
		December 31,
	2016	2017	2018
	RMB	RMB	RMB
Numerator:
Net loss attributable to ordinary shareholders	(232,720,922)	(184,662,871)	(349,027,476)
Numerator for basic and diluted net loss per share calculation	(232,720,922)	(184,662,871)	(349,027,476)

Denominator:
Weighted average number of shares outstanding used in computing net loss per share	10,414,325	26,295,181	65,834,876

Denominator for basic and diluted net loss per share calculation	10,414,325	26,295,181	65,834,876

Net loss per share attributable to ordinary shareholders
—Basic and diluted	(22.35)	(7.02)	(5.30)

Schedule of antidilutive securities


	For the Year Ended
	December 31,
	2017	2018
Share options	4,265,750	5,314,246
Restricted share units	—	100,000
Restricted ordinary shares	32,689,010	—
Series Seed Preferred Shares	30,000,000	—
Series A Preferred Shares	25,278,350	—
Convertible loan	10,119,329	—

REVENUE INFORMATION (Tables)

12 Months Ended

Dec. 31, 2018

REVENUE INFORMATION

Schedule of net revenues


	For the Year Ended
	December 31,
	2016	2017	2018
	RMB	RMB	RMB
Electronic scooter sales	337,920,673	709,595,841	1,370,522,269
Accessory and Spare parts sales	14,920,309	49,159,080	91,373,179
Service revenues	1,969,066	10,613,080	15,885,856
Net revenues	354,810,048	769,368,001	1,477,781,304

Schedule of the Group's revenue based on geographic areas


	For the Year Ended
	December 31,
	2016	2017	2018
	RMB	RMB	RMB
PRC	353,041,492	731,423,647	1,318,657,227
Europe	1,118,230	36,257,165	148,963,330
Others	650,326	1,687,189	10,160,747
Net revenues	354,810,048	769,368,001	1,477,781,304

COMMITMENTS AND CONTINGENCIES (Tables)

12 Months Ended

Dec. 31, 2018

COMMITMENTS AND CONTINGENCIES

Schedule of future minimum lease commitments


Year ending December 31,		RMB
2019		6,943,633
2020		3,333,014
2021		1,293,531

PARENT COMPANY ONLY CONDENSED FINANCIAL INFORMATION (Tables)

12 Months Ended

Dec. 31, 2018

PARENT COMPANY ONLY CONDENSED FINANCIAL INFORMATION

Schedule of condensed balance sheets


	As of December 31,
	2017	2018
	RMB	RMB
Assets
Current assets
Cash	39,678,102	149,901,311
Term deposit	—	27,452,663
Restricted cash—current	52,273,600	124,357,114
Amount due from subsidiaries and consolidated VIE and VIE's subsidiaries	53,490,993	405,843,735
Prepayments and other current assets	—	3,707,403
Total current assets	145,442,695	711,262,226
Non-current assets:
Investment in subsidiaries and consolidated VIE and VIE's subsidiaries	—	—
Restricted cash—non current	65,342,000	—
Total non-current assets	65,342,000	—
Total assets	210,784,695	711,262,226

Liabilities
Current liabilities
Convertible loan	151,557,796	—
Amount due to subsidiaries and consolidated VIE and VIE’s subsidiaries	—	4,262,270
Accrued expenses and other current liabilities	—	7,593,082
Total current liabilities and total liabilities	151,557,796	11,855,352
Mezzanine Equity
Series A-1 Redeemable Convertible Preferred Shares	130,684,003	—
Series A-2 Redeemable Convertible Preferred Shares	39,205,192	—
Series A-3 Redeemable Convertible Preferred Shares	67,955,320	—
Total mezzanine equity	237,844,515	—

Shareholders' (deficit)/equity:
Ordinary Shares	39,948	—
Class A Ordinary Shares	—	83,120
Class B Ordinary Shares	—	12,839
Series Seed Convertible Preferred Shares	18,436	—
Additional paid-in capital	440,265,896	1,717,483,548
Accumulated other comprehensive income/(loss)	3,281,862	(25,394,429)
Accumulated deficit	(622,223,758)	(992,778,204)
Total shareholders' (deficit)/equity	(178,617,616)	699,406,874
Total liabilities, mezzanine equity and shareholders' (deficit)/equity	210,784,695	711,262,226

Schedule of condensed statements of results of operations


	For the Year Ended December 31,
	2016	2017	2018
	RMB	RMB	RMB
Total operating expenses	(393,856)	(163,640)	(1,908,246)
Changes in fair value of a convertible loan	—	(43,006,399)	(34,499,858)
Share of losses from subsidiaries, VIE and VIE's subsidiaries	(198,821,537)	(62,527,098)	(331,955,300)
Interest income	150,594	366,795	2,011,390
Foreign currency exchange (losses)/gain	(4,544,844)	3,192,896	(364)
Loss before income tax	(203,609,643)	(102,137,446)	(366,352,378)
Income tax expense	—	—	—
Net loss	(203,609,643)	(102,137,446)	(366,352,378)

Schedule of condensed statements of cash flows


	For the Year Ended
	December 31,
	2016	2017	2018
	RMB	RMB	RMB
Net cash (used in)/provided by operating activities	(76,650,478)	12,825,090	(352,222,011)
Net cash used in investing activities	—	—	(19,902,073)
Net cash provided by financing activities	104,354,252	—	481,123,035
Effect of foreign currency exchange rate changes on cash	(498,905)	(1,889,261)	1,224,258
Net increase in cash	27,204,869	10,935,829	110,223,209
Cash at the beginning of the year	1,537,404	28,742,273	39,678,102
Cash at the end of the year	28,742,273	39,678,102	149,901,311

DESCRIPTION OF ORGANIZATION AND PRINCIPAL ACTIVITIES - Principal terms of VIE Agreements (Details)	12 Months Ended
	Dec. 31, 2018 CNY (¥)
DESCRIPTION OF ORGANIZATION AND PRINCIPAL ACTIVITIES
Percentage of monthly net profits under Exclusive Business Cooperation Agreement	100.00%
Maximum equity holders' interests permitted under Exclusive Option Agreement	¥ 100
Minimum value of material assets for dispositions under Exclusive Option Agreement	¥ 100,000

DESCRIPTION OF ORGANIZATION AND PRINCIPAL ACTIVITIES - Group's VIE information (Details)	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)	Dec. 31, 2018 CNY (¥)
Group's VIE information
Cash	$ 82,766,285		¥ 111,996,325		¥ 569,059,591
Short-term investments	17,488,390		85,187,718		120,241,425
Accounts receivable, net	7,915,765		10,382,112		54,424,845
Inventories	20,708,633		88,225,965		142,382,205
Prepayments and other current assets	3,915,345		7,349,583		26,919,954
Total current assets	162,859,922		407,688,903		1,119,743,397
Property and equipment, net	5,961,046		28,696,602		40,985,174
Intangible assets, net	1,122,501		1,277,467		7,717,754
Other non-current assets	2,444,256		626,605		16,805,474
Total assets	172,387,725		503,631,577		1,185,251,799
Short-term bank borrowings	26,176,715		168,234,207		179,978,003
Accounts payable	36,312,398		124,937,465		249,665,890
Advances from customers	2,982,454		48,503,389		20,505,861
Deferred revenue - current	1,842,241		9,853,361		12,666,330
Accrued expenses and other current liabilities	19,516,258		75,412,869		134,184,026
Total current liabilities	86,830,066		578,499,087		597,000,110
Warranty - non current	2,561,245		12,378,751		17,609,842
Deferred revenue - non current	34,150		144,700		234,801
Total liabilities	89,425,461		591,022,538		614,844,753
Net revenues	214,934,376	¥ 1,477,781,304	769,368,001	¥ 354,810,048
Net loss	(50,763,942)	(349,027,476)	(184,662,871)	(232,720,922)
Net cash used in operating activities	1,131,460	7,779,366	80,063,278	(123,053,734)
Net cash used in investing activities	(15,066,491)	(103,589,651)	(55,928,949)	(59,949,934)
Net cash provided by financing activities	80,777,047	555,382,588	2,414,710	225,011,777
Effect of foreign currency exchange rate changes on cash	(364,921)	(2,509,037)	(5,673,424)	2,061,790
Net increase in cash	66,477,095	457,063,266	20,875,615	44,069,899
Cash at the beginning of the year	16,289,190	111,996,325	91,120,710	47,050,811
Cash at the end of the year	$ 82,766,285	569,059,591	111,996,325	91,120,710
VIE
Group's VIE information
Cash			71,792,874		90,723,253
Short-term investments			85,187,718		120,241,425
Accounts receivable, net			10,382,112		54,424,845
Inventories			88,225,965		142,155,411
Prepayments and other current assets			7,349,583		22,711,514
Amounts due from related parties					4,262,270
Total current assets			262,938,252		434,518,718
Property and equipment, net			28,696,602		40,580,352
Intangible assets, net			1,277,467		580,667
Other non-current assets			626,605		16,805,475
Total assets			293,538,926		492,485,212
Short-term bank borrowings			168,234,207		179,978,003
Accounts payable			124,937,465		249,665,890
Amounts due to related parties			144,169,442		211,250,230
Advances from customers			48,503,389		20,505,861
Deferred revenue - current			9,853,361		12,666,330
Accrued expenses and other current liabilities			75,382,869		119,242,975
Total current liabilities			571,080,733		793,309,289
Warranty - non current			12,378,751		17,609,842
Deferred revenue - non current			144,700		234,801
Total liabilities			583,604,184		¥ 811,153,932
Net revenues		1,477,593,628	769,368,001	354,810,048
Net loss		(294,156,973)	(145,154,084)	(227,081,999)
Net cash used in operating activities		14,379,166	(2,423,156)	(80,026,685)
Net cash used in investing activities		(74,333,070)	(55,928,949)	(59,949,934)
Net cash provided by financing activities		78,199,492	68,703,310	185,610,980
Effect of foreign currency exchange rate changes on cash		684,791	(813,270)	196,441
Net increase in cash		18,930,379	9,537,935	45,830,802
Cash at the beginning of the year		71,792,874	62,254,939	16,424,137
Cash at the end of the year		¥ 90,723,253	¥ 71,792,874	¥ 62,254,939

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Cash (Details) - CNY (¥)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Cash
Total cash balances held at financial institutions	¥ 568,739,787	¥ 111,990,151
Minimum
Cash
Original maturities of term deposit	3 months
Maximum
Cash
Original maturities of term deposit	1 year
PRC
Cash
Total cash balances held at financial institutions	¥ 301,112,759	74,682,672
PRC \| Denominated in RMB
Cash
Total cash balances held at financial institutions	145,529,365	51,157,225
PRC \| Denominated in USD
Cash
Total cash balances held at financial institutions	155,583,394	23,525,190
PRC \| Denominated in EUR
Cash
Total cash balances held at financial institutions		257
United States
Cash
Total cash balances held at financial institutions	4,038,742	37,307,479
United States \| Denominated in USD
Cash
Total cash balances held at financial institutions	4,038,742	¥ 37,307,479
Hong Kong SAR
Cash
Total cash balances held at financial institutions	263,588,286
Hong Kong SAR \| Denominated in USD
Cash
Total cash balances held at financial institutions	¥ 263,588,286

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Inventories, Property and Equipment, net (Details)	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
Inventories
Inventories write downs	$ 2,654,993	¥ 18,254,406	¥ 0	¥ 0
Machinery and equipment \| Minimum
Estimated useful lives
Property, plant and equipment, useful life	3 years	3 years
Machinery and equipment \| Maximum
Estimated useful lives
Property, plant and equipment, useful life	10 years	10 years
Furniture
Estimated useful lives
Property, plant and equipment, useful life	3 years	3 years
Leasehold improvements
Estimated useful lives
Property, plant and equipment, useful life	3 years	3 years
Office and electronic equipment \| Minimum
Estimated useful lives
Property, plant and equipment, useful life	2 years	2 years
Office and electronic equipment \| Maximum
Estimated useful lives
Property, plant and equipment, useful life	5 years	5 years
Motor vehicles
Estimated useful lives
Property, plant and equipment, useful life	4 years	4 years

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Value added taxes, Revenue recognition (Details)	12 Months Ended
	Dec. 31, 2018	May 01, 2018	Apr. 30, 2018
Value added taxes
VAT rate (in percentage)		16.00%	17.00%
Revenue recognition
Return and refund policy term (in days)	7 days
Minimum
Revenue recognition
Free service period	1 year
Maximum
Revenue recognition
Free service period	2 years

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Concentration and risk (Details)	12 Months Ended
	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)
Concentration and risk
Accounts receivable		¥ 10,382,112		$ 7,915,765	¥ 54,424,845
Advances from customers		48,503,389		2,982,454	20,505,861
Accounts payable		124,937,465		$ 36,312,398	249,665,890
Total purchases \| Suppliers risk \| Supplier F
Concentration and risk
Total purchases	¥ 193,555,999
Concentration risk (as a percent)	15.00%
Total purchases \| Suppliers risk \| Supplier A
Concentration and risk
Total purchases	¥ 150,385,652	¥ 187,065,077	¥ 51,368,000
Concentration risk (as a percent)	12.00%	21.00%	12.00%
Total purchases \| Suppliers risk \| Supplier B
Concentration and risk
Total purchases		¥ 152,966,930	¥ 61,900,615
Concentration risk (as a percent)		18.00%	14.00%
Total purchases \| Suppliers risk \| Supplier C
Concentration and risk
Total purchases			¥ 60,072,473
Concentration risk (as a percent)			14.00%
Accounts receivable \| Customer risk \| Customer Y
Concentration and risk
Accounts receivable		¥ 3,904,087			45,980,177
Concentration risk (as a percent)	84.00%	32.00%
Accounts receivable \| Customer risk \| Customer Z
Concentration and risk
Accounts receivable		¥ 1,471,144
Concentration risk (as a percent)		12.00%
Advances from customers \| Customer risk \| Customer V
Concentration and risk
Advances from customers		¥ 9,021,739
Concentration risk (as a percent)		19.00%
Accounts payable \| Suppliers risk \| Supplier F
Concentration and risk
Accounts payable					25,702,037
Concentration risk (as a percent)	10.00%
Accounts payable \| Suppliers risk \| Supplier B
Concentration and risk
Accounts payable		¥ 17,048,400
Concentration risk (as a percent)		14.00%
Accounts payable \| Suppliers risk \| Supplier D
Concentration and risk
Accounts payable		¥ 12,623,108
Concentration risk (as a percent)		10.00%
Accounts payable \| Suppliers risk \| Supplier E
Concentration and risk
Accounts payable					¥ 26,483,893
Concentration risk (as a percent)	11.00%

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Statutory Reserves (Details) - CNY (¥)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Percentage of after tax profit, transferred annually by PRC subsidiaries to statutory surplus fund	10.00%
Maximum percentage criteria for appropriation of after-tax profit of PRC subsidiaries to statutory surplus fund (as a percent)	50.00%
Amount of appropriations made to statutory surplus fund and discretionary surplus fund	¥ 0	¥ 0	¥ 0

SHORT-TERM INVESTMENTS (Details)	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)
SHORT-TERM INVESTMENTS
Aggregate cost basis		¥ 120,000,000	¥ 85,000,000
Gross unrealized holding gain		241,425	187,718
Aggregate fair value	$ 17,488,390	120,241,425	85,187,718
Gross unrealized holding losses		¥ 0	¥ 0

ACCOUNTS RECEIVABLES, NET (Details)	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
ACCOUNTS RECEIVABLES, NET
Accounts receivable		¥ 54,652,991	¥ 12,338,357
Allowance for doubtful accounts		(228,146)	(1,956,245)	¥ (47,846)
Accounts Receivable, net	$ 7,915,765	¥ 54,424,845	¥ 10,382,112

ACCOUNTS RECEIVABLES, NET - Movement of the allowance for doubtful accounts (Details) - CNY (¥)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Summary of movement of the allowance for doubtful accounts
Balance at the beginning of the year	¥ 1,956,245	¥ 47,846
Additions/ (reversals) charged to bad debt expense	(1,215,464)	1,908,399	¥ 47,846
Write-off of bad debt allowance	(512,635)
Balance at the end of the year	¥ 228,146	¥ 1,956,245	¥ 47,846

INVENTORIES (Details)	12 Months Ended
INVENTORIES (Details)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)
INVENTORIES
Raw materials			¥ 120,290,456	¥ 72,473,857
Works in progress			1,948,838	1,522,033
Finished goods			20,142,911	14,230,075
Inventories		$ 20,708,633	¥ 142,382,205	¥ 88,225,965
Loss on inventories damaged from a warehouse fire accident	¥ 18,254,406

PREPAYMENTS AND OTHER CURRENT ASSETS (Details)	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)
PREPAYMENTS AND OTHER CURRENT ASSETS
Advances to suppliers		¥ 15,507,866	¥ 2,772,494
Deductible input VAT and VAT rebates receivable		7,855,998	3,469,724
Staff advances		447,791	1,029,409
Others		3,108,299	77,956
Prepayments and Other Current Assets	$ 3,915,345	¥ 26,919,954	¥ 7,349,583

PROPERTY AND EQUIPMENT, NET (Details)	12 Months Ended
PROPERTY AND EQUIPMENT, NET (Details)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)
Property, Plant and Equipment [Line Items]
Property and Equipment		¥ 42,559,611			¥ 71,236,365
Less: Accumulated depreciation		(13,863,009)			(30,251,191)
Property and Equipment, net		28,696,602		$ 5,961,046	40,985,174
Depreciation expenses	¥ 16,808,987	9,049,769	¥ 4,490,972
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property and Equipment		17,453,885			22,615,657
Furniture
Property, Plant and Equipment [Line Items]
Property and Equipment		15,499,944			36,630,720
Office and electronic equipment
Property, Plant and Equipment [Line Items]
Property and Equipment		7,253,743			9,071,471
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and Equipment		1,897,392			2,116,266
Motor vehicles
Property, Plant and Equipment [Line Items]
Property and Equipment		¥ 454,647			¥ 802,251

PROPERTY AND EQUIPMENT, NET - Depreciation expense (Details) - CNY (¥)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Depreciation expense on property and equipment
Total depreciation expense	¥ 16,808,987	¥ 9,049,769	¥ 4,490,972
Cost of revenues
Depreciation expense on property and equipment
Total depreciation expense	4,638,662	4,217,126	2,405,046
General and administrative expenses
Depreciation expense on property and equipment
Total depreciation expense	2,261,620	1,873,711	1,120,533
Selling and marketing expenses
Depreciation expense on property and equipment
Total depreciation expense	9,438,501	2,646,204	264,665
Research and development expenses
Depreciation expense on property and equipment
Total depreciation expense	¥ 470,204	¥ 312,728	¥ 700,728

INTANGIBLE ASSETS, NET (Details)	12 Months Ended
INTANGIBLE ASSETS, NET (Details)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)
INTANGIBLE ASSETS, NET
Gross carrying amount					¥ 12,048,505
Accumulated amortization					(4,330,751)
Net carrying amount		¥ 1,277,467		$ 1,122,501	7,717,754
Amortization expenses	¥ 2,072,389	¥ 696,800	¥ 696,800
Estimated amortization expenses for the year ending 2019					2,293,568
Estimated amortization expenses for the year ending 2020					1,712,901
Estimated amortization expenses for the year ending 2021					1,712,901
Estimated amortization expenses for the year ending 2022					1,712,901
Estimated amortization expenses for the year ending 2023					285,483
Trademarks
INTANGIBLE ASSETS, NET
Intangible assets, amortization period	5 years
Gross carrying amount					8,564,505
Accumulated amortization					(1,427,418)
Net carrying amount					7,137,087
Domain name
INTANGIBLE ASSETS, NET
Intangible assets, amortization period	5 years	5 years
Gross carrying amount		¥ 3,484,000			3,484,000
Accumulated amortization		(2,206,533)			(2,903,333)
Net carrying amount		¥ 1,277,467			¥ 580,667

OTHER NON-CURRENT ASSETS (Details)	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)
OTHER NON-CURRENT ASSETS
Prepayments for land use right		¥ 12,329,652
Others		4,475,822	¥ 626,605
Other non-current assets	$ 2,444,256	¥ 16,805,474	¥ 626,605

SHORT-TERM BANK BORROWINGS AND RESTRICTED CASH (Details)		1 Months Ended
	Feb. 08, 2018 CNY (¥)	Dec. 31, 2018 USD ($)	Nov. 30, 2017 USD ($)	Aug. 31, 2017 CNY (¥)	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2018 CNY (¥)	Nov. 30, 2018 USD ($)	Oct. 31, 2018	Dec. 31, 2017 CNY (¥)	Nov. 30, 2017 CNY (¥)	Mar. 31, 2016 CNY (¥)	Dec. 31, 2015 CNY (¥)
SHORT-TERM BANK BORROWINGS AND RESTRICTED CASH
Short-term bank borrowings							¥ 179,978,003			¥ 168,234,207
Restricted cash-non current										65,342,000
Restricted cash-current		$ 26,072,680					179,262,714			104,547,200
East West Bank loan
SHORT-TERM BANK BORROWINGS AND RESTRICTED CASH
Short-term bank borrowings							99,978,003			98,234,207
Number of line of credit agreements					2	2
Debt term					1 year	1 year
Face amount							99,978,003			¥ 98,234,207
Maximum credit facility amount												¥ 100,000,000	¥ 100,000,000
Interest rate (in percent)					2.80%	2.80%			4.75%	4.50%		2.80%	2.80%
Collateral deposits \| $					$ 16,000,000	$ 16,000,000
Restricted cash-non current							109,811,200			¥ 104,547,200
Bank of China loan
SHORT-TERM BANK BORROWINGS AND RESTRICTED CASH
Short-term bank borrowings							20,000,000			10,000,000
Debt term	1 year	1 year		6 months
Face amount	¥ 20,000,000			¥ 10,000,000			¥ 20,000,000
Interest rate (in percent)	4.5675%	4.5675%		4.5675%			4.5675%
SPD Silicon Valley Bank loan
SHORT-TERM BANK BORROWINGS AND RESTRICTED CASH
Short-term bank borrowings							¥ 60,000,000			60,000,000
Debt term			1 year
Face amount							¥ 60,000,000			¥ 60,000,000
Maximum credit facility amount											¥ 60,000,000
Interest rate (in percent)		4.35%					4.35%			4.35%
Collateral deposits \| $			$ 10,000,000					$ 10,000,000
Restricted cash-non current							¥ 0			¥ 65,342,000
Restricted cash-current							¥ 69,451,514			¥ 0

CONVERTIBLE LOAN (Details)	Mar. 26, 2018 $ / shares shares	Dec. 16, 2016 USD ($)	Mar. 26, 2018 CNY (¥)	Dec. 16, 2016 CNY (¥)
Series A-3 Redeemable Convertible Preferred Shares
CONVERTIBLE LOAN
Number of shares issued on debt conversion \| shares	10,119,329
Conversion price per share \| $ / shares	$ 1.66
Convertible Loan
CONVERTIBLE LOAN
Convertible loan		$ 16,827,000	¥ 181,112,874	¥ 115,808,672
Debt term		1 year
Interest rate (in percent)		5.00%		5.00%
Percentage of entity valuation		80.00%		80.00%
Entity valuation \| $		$ 260,400,000

ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES (Details)	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)
ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES
Accrued payroll and social insurance		¥ 32,008,825	¥ 28,536,755
Warranty-current		31,262,442	18,269,927
Sales rebate		34,029,433	14,317,285
Deposits		16,360,762	8,784,383
Deferred ADR income		4,250,126
Other taxes payable		3,656,732	1,099,932
IPO cost payable		3,130,639
Interest payable		318,774	167,269
Others		9,166,293	4,237,318
Accrued expenses and other current liabilities	$ 19,516,258	¥ 134,184,026	¥ 75,412,869

ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES - Warranty terms (Details)	12 Months Ended
	Dec. 31, 2018 km
Electric motor
Warranty terms
Warranty term	24 months
Kilometer covered under warranty	30,000
Lithium-ion battery packs, model 1
Warranty terms
Warranty term	24 months
Kilometer covered under warranty	20,000
Lithium-ion battery packs, model 2
Warranty terms
Warranty term	36 months
Kilometer covered under warranty	30,000
Minimum
Warranty terms
Warranty term	6 months
Minimum \| Smart electric-scooters
Warranty terms
Warranty term	6 months
Maximum
Warranty terms
Warranty term	3 years
Maximum \| Smart electric-scooters
Warranty terms
Warranty term	24 months

ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES - Movement of provision (Details) - CNY (¥)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Movement of provision
Accrued warranty-beginning of year	¥ 30,648,678	¥ 17,649,411	¥ 7,688,887
Accrual for warranties issued during the year	29,346,974	27,395,169	15,315,474
Warranty claims paid	(7,923,760)	(14,395,902)	(5,354,950)
Pre-existing warranty expired	(3,199,608)
Accrued warranty-end of year	¥ 48,872,284	¥ 30,648,678	¥ 17,649,411

REDEEMABLE CONVERTIBLE PREFERRED SHARES (Details)								12 Months Ended
REDEEMABLE CONVERTIBLE PREFERRED SHARES (Details)	Mar. 26, 2018 USD ($) $ / shares shares	Mar. 26, 2018 CNY (¥) shares	Jan. 29, 2016 USD ($) $ / shares shares	Jan. 29, 2016 CNY (¥)	May 27, 2015 USD ($) $ / shares shares	May 27, 2015 CNY (¥)	Mar. 05, 2015 USD ($) shares	Dec. 31, 2017 USD ($)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)	Dec. 31, 2015 USD ($)	Dec. 31, 2015 CNY (¥)	Mar. 26, 2018 CNY (¥) shares	Dec. 16, 2016 USD ($)	Dec. 16, 2016 CNY (¥)
REDEEMABLE CONVERTIBLE PREFERRED SHARES
Issuance of convertible loan							$ 3,900,000			¥ 115,808,672
Interest on convertible loan \| $							$ 0
Convertible Loan
REDEEMABLE CONVERTIBLE PREFERRED SHARES
Outstanding principal converted \| $	$ 16,827,000
Convertible loan carrying amount													¥ 181,112,874	$ 16,827,000	¥ 115,808,672
Series A1 Redeemable Convertible Preferred Shares
REDEEMABLE CONVERTIBLE PREFERRED SHARES
Preferred shares, issued \| shares					16,666,667		3,250,000
Issued price per share \| $ / shares					$ 1.20
Proceeds from issuance of Redeemable Convertible Preferred Shares					$ 16,100,000	¥ 101,208,371		$ 6,600,000	¥ 43,068,820	43,068,820	$ 9,500,000	¥ 58,139,551
Series A-2 Redeemable Convertible Preferred Shares
REDEEMABLE CONVERTIBLE PREFERRED SHARES
Preferred shares, issued \| shares					3,608,247
Issued price per share \| $ / shares					$ 1.66
Proceeds from issuance of Redeemable Convertible Preferred Shares					$ 6,000,000	¥ 36,720,422
Series A-3 Redeemable Convertible Preferred Shares
REDEEMABLE CONVERTIBLE PREFERRED SHARES
Preferred shares, issued \| shares			5,003,436
Issued price per share \| $ / shares			$ 2.08
Conversion price per share \| $ / shares	$ 1.66
Number of shares issued on debt conversion \| shares	10,119,329	10,119,329
Proceeds from issuance of Redeemable Convertible Preferred Shares			$ 10,400,000	¥ 67,883,227						¥ 67,883,227
Series B Preferred Shares
REDEEMABLE CONVERTIBLE PREFERRED SHARES
Preferred shares, issued \| shares													5,137,859
Issued price per share \| $ / shares	$ 4.96
Proceeds from issuance of Redeemable Convertible Preferred Shares	$ 25,500,000	¥ 161,392,196

REDEEMABLE CONVERTIBLE PREFERRED SHARES - Series A Preferred Shares activities (Details)		1 Months Ended	12 Months Ended
	Feb. 28, 2018	Mar. 31, 2018	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥) shares	Dec. 31, 2016 CNY (¥)	Dec. 31, 2018 USD ($) shares
Conversion Rights
Minimum percentage of shareholders approval needed to waive the foregoing pre-offering valuation and gross proceeds requirements \| $						$ 1,000,000,000
Minimum market capitalization criteria for Qualified IPO \| $						$ 100,000,000
Liquidation Preferences
Balance at beginning			¥ 237,844,515	¥ 252,506,413	¥ 125,975,835
Issuance of preferred shares			342,505,070		67,883,227
Subscription receivable					43,068,820
Foreign currency translation adjustment			47,712,689	(14,661,898)	15,578,531
Conversion to Ordinary Shares			¥ (628,062,274)
Balance at end				¥ 237,844,515	252,506,413
Series A Preferred Shares
Conversion Rights
Conversion of Preferred Shares in to ordinary share \| shares				1		1
Minimum percentage of shareholders approval needed to convert Preferred Shares into Ordinary Shares						0.67%
Minimum percentage of holders consent for qualified IPO			0.67%
Liquidation Preferences
Percentage of liquidation preference on preferred share issue price	150.00%	150.00%
Series A1 Redeemable Convertible Preferred Shares
Liquidation Preferences
Balance at beginning			¥ 130,684,003	¥ 138,740,003	129,872,003
Foreign currency translation adjustment			8,090,000	(8,056,000)	8,868,000
Conversion to Ordinary Shares			(138,774,003)
Balance at end				130,684,003	138,740,003
Series A1 Redeemable Convertible Preferred Shares \| Subscription receivable
Liquidation Preferences
Balance at beginning					(42,857,760)
Subscription receivable					43,068,820
Foreign currency translation adjustment					(211,060)
Series A-2 Redeemable Convertible Preferred Shares
Liquidation Preferences
Balance at beginning			39,205,192	41,621,992	38,961,592
Foreign currency translation adjustment			2,427,000	(2,416,800)	2,660,400
Conversion to Ordinary Shares			(41,632,192)
Balance at end				39,205,192	41,621,992
Series A-3 Redeemable Convertible Preferred Shares
Liquidation Preferences
Balance at beginning			67,955,320	72,144,418
Issuance of preferred shares			181,112,874		67,883,227
Foreign currency translation adjustment			21,651,035	(4,189,098)	4,261,191
Conversion to Ordinary Shares			(270,719,229)
Balance at end				¥ 67,955,320	¥ 72,144,418
Series B Preferred Shares
Liquidation Preferences
Percentage of liquidation preference on preferred share issue price		150.00%
Issuance of preferred shares			161,392,196
Foreign currency translation adjustment			15,544,654
Conversion to Ordinary Shares			¥ (176,936,850)

ORDINARY SHARES AND SERIES SEED PREFERRED SHARES (Details)			1 Months Ended			12 Months Ended
	Mar. 26, 2018 USD ($) shares	Mar. 26, 2018 CNY (¥) shares	Oct. 31, 2018 USD ($) $ / shares shares	Oct. 31, 2018 CNY (¥) shares	Sep. 30, 2018 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 $ / shares shares
ORDINARY SHARES AND SERIES SEED PREFERRED SHARES
Ordinary shares, authorized					5,000,000,000			444,721,650
Ordinary shares, par value (in dollars per share) \| $ / shares								$ 0.0001
Consideration for repurchase of ordinary shares						$ 611,204	¥ 4,202,335
Authorized share capital \| $					$ 500,000
Ordinary shares, outstanding								64,570,520
Niu Holding Inc.
ORDINARY SHARES AND SERIES SEED PREFERRED SHARES
Number of ordinary shares repurchased	432,000	432,000
Consideration for repurchase of ordinary shares	$ 665,000	¥ 4,202,335
Share re-classified and re-designated as Class B ordinary shares (in shares)					14,027,020
ELLY Holdings
ORDINARY SHARES AND SERIES SEED PREFERRED SHARES
Share re-classified and re-designated as Class B ordinary shares (in shares)					6,615,000
Ordinary shares
ORDINARY SHARES AND SERIES SEED PREFERRED SHARES
Ordinary shares, authorized					50,000,000
Ordinary shares, par value (in dollars per share) \| $ / shares					$ 0.0001
Class A Ordinary Shares
ORDINARY SHARES AND SERIES SEED PREFERRED SHARES
Ordinary shares, authorized					4,900,000,000	4,900,000,000
Ordinary shares, par value (in dollars per share) \| $ / shares					$ 0.0001	$ 0.0001
Basis of converted preferred shares to each ordinary share					1
Share converted to Class A ordinary shares (in shares)					1
Ordinary shares, outstanding						128,032,038
Class A Ordinary Shares \| IPO
ORDINARY SHARES AND SERIES SEED PREFERRED SHARES
Number of newly issued ordinary shares under IPO			14,000,000	14,000,000
Public offering price (in dollars per share) \| $ / shares			$ 4.5
Net proceeds after deducting underwriting commissions and discounts			$ 58,590,000	¥ 406,538,433
Class B Ordinary Shares
ORDINARY SHARES AND SERIES SEED PREFERRED SHARES
Ordinary shares, authorized					50,000,000	50,000,000
Ordinary shares, par value (in dollars per share) \| $ / shares					$ 0.0001	$ 0.0001
Basis of re-classified and re-designated to each Class B ordinary share					1
Ordinary shares, outstanding						20,642,020
Series Seed Convertible Preferred Shares
ORDINARY SHARES AND SERIES SEED PREFERRED SHARES
Preferred shares, outstanding						0		30,000,000
Preferred Shares, par value (in dollars per share) \| $ / shares					$ 0.0001	$ 0.0001		$ 0.0001
Basis of converted preferred shares to each ordinary share					1
Share converted to Class A ordinary shares (in shares)					30,000,000
Preferred shares, authorized						0		30,000,000
Series A1 Redeemable Convertible Preferred Shares
ORDINARY SHARES AND SERIES SEED PREFERRED SHARES
Outstanding temporarily equity (in shares)						0		16,666,667
Temporary equity value per share \| $ / shares					$ 0.0001	$ 0.0001		$ 0.0001
Share converted to Class A ordinary shares (in shares)					16,666,667
Series A-2 Redeemable Convertible Preferred Shares
ORDINARY SHARES AND SERIES SEED PREFERRED SHARES
Outstanding temporarily equity (in shares)						0		3,608,247
Temporary equity value per share \| $ / shares					$ 0.0001	$ 0.0001		$ 0.0001
Share converted to Class A ordinary shares (in shares)					3,608,247
Series A-3 Redeemable Convertible Preferred Shares
ORDINARY SHARES AND SERIES SEED PREFERRED SHARES
Outstanding temporarily equity (in shares)						0		5,003,436
Temporary equity value per share \| $ / shares					$ 0.0001	$ 0.0001		$ 0.0001
Share converted to Class A ordinary shares (in shares)					15,122,765
Series B Preferred Shares
ORDINARY SHARES AND SERIES SEED PREFERRED SHARES
Preferred shares, outstanding					5,137,859
Preferred Shares, par value (in dollars per share) \| $ / shares					$ 0.0001
Share converted to Class A ordinary shares (in shares)					5,137,859

SHARE-BASED COMPENSATION - Restricted ordinary shares (Details)					1 Months Ended		12 Months Ended
	Oct. 19, 2018 CNY (¥)	Jun. 08, 2018 CNY (¥)	May 27, 2016	Jan. 07, 2016 CNY (¥) shares	Feb. 29, 2016 CNY (¥)	May 31, 2015 $ / shares shares	Dec. 31, 2018 $ / shares	Dec. 31, 2018 CNY (¥) shares	Dec. 31, 2017 $ / shares shares	Dec. 31, 2017 CNY (¥) shares	Dec. 31, 2016 CNY (¥)
SHARE-BASED COMPENSATION
Ordinary shares, outstanding \| shares									64,570,520	64,570,520
Research and development expenses
SHARE-BASED COMPENSATION
Share-based compensation expenses	¥ 8,935,076
General and administrative expenses
SHARE-BASED COMPENSATION
Share-based compensation expenses	¥ 10,535,229	¥ 33,537,572
Restricted ordinary shares
SHARE-BASED COMPENSATION
Vesting period						4 years
Period to repurchase restricted ordinary shares						60 days
Estimated fair value of ordinary shares \| $ / shares						$ 0.53
Share-based compensation expenses, upon waiver of service condition					¥ 7,574,133
Modification of restricted ordinary shares \| shares				3,307,500
Unrecognized compensation cost				¥ 9,803,035
Share-based compensation expenses								¥ 226,242,279		¥ 59,230,943	¥ 75,584,806
Total fair value of shares vested								¥ 264,075,922		¥ 58,848,966	73,692,770
Number of Shares
Outstanding at beginning of period (in shares) \| shares								32,689,010
Granted (in shares) \| shares						59,459,020
Vested (in shares) \| shares								(32,689,010)
Outstanding at end of period (in shares) \| shares										32,689,010
Weighted average grant date fair value
Outstanding at beginning of period (in dollars per share) \| $ / shares							$ 0.57
Vested (in dollars per share) \| $ / shares							$ 0.57
Outstanding at end of period (in dollars per share) \| $ / shares									$ 0.57
Restricted ordinary shares \| Research and development expenses
SHARE-BASED COMPENSATION
Share-based compensation expenses								¥ 18,371,203		¥ 13,045,853	12,821,215
Restricted ordinary shares \| General and administrative expenses
SHARE-BASED COMPENSATION
Share-based compensation expenses		173,156,580						¥ 207,871,076		¥ 46,185,090	¥ 62,763,591
Restricted ordinary shares \| Mr. Yi'nan Li
SHARE-BASED COMPENSATION
Restricted ordinary shares not to repurchased (in shares)		9,798,125
Restricted ordinary shares \| Mr. Mingming Huang
SHARE-BASED COMPENSATION
Restricted ordinary shares not to repurchased (in shares)		¥ 451,000
Restricted ordinary shares \| ELLY Holdings
SHARE-BASED COMPENSATION
Vesting period				4 years
Shares Issued / Transferred \| shares				3,307,500
Ordinary shares, outstanding \| shares				6,615,000
Restricted ordinary shares \| Smart Power Group Limited
SHARE-BASED COMPENSATION
Vesting period				3 years
Shares Issued / Transferred \| shares				1,804,000
Restricted ordinary shares \| Smart Power Group Limited \| Tranche One
SHARE-BASED COMPENSATION
Vesting percentage			25.00%
Restricted ordinary shares \| Smart Power Group Limited \| Tranche Two
SHARE-BASED COMPENSATION
Vesting percentage								75.00%

SHARE-BASED COMPENSATION - Compensation expense recognized for restricted ordinary shares (Details) - CNY (¥)			12 Months Ended
	Oct. 19, 2018	Jun. 08, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Research and development expenses
SHARE-BASED COMPENSATION
Total share-based compensation expenses	¥ 8,935,076
General and administrative expenses
SHARE-BASED COMPENSATION
Total share-based compensation expenses	¥ 10,535,229	¥ 33,537,572
Restricted ordinary shares
SHARE-BASED COMPENSATION
Total share-based compensation expenses			¥ 226,242,279	¥ 59,230,943	¥ 75,584,806
Unrecognized compensation expense			0
Restricted ordinary shares \| Research and development expenses
SHARE-BASED COMPENSATION
Total share-based compensation expenses			18,371,203	13,045,853	12,821,215
Restricted ordinary shares \| General and administrative expenses
SHARE-BASED COMPENSATION
Total share-based compensation expenses		¥ 173,156,580	¥ 207,871,076	¥ 46,185,090	¥ 62,763,591

SHARE-BASED COMPENSATION - Transfer of ordinary shares (Details) - CNY (¥)	Oct. 19, 2018	Jun. 08, 2018
SHARE-BASED COMPENSATION
Number of ordinary shares consideration transferred		2,000,000
Consideration paid for transfer of ordinary shares		¥ 0
General and administrative expenses
SHARE-BASED COMPENSATION
Share-based compensation expenses	¥ 10,535,229	¥ 33,537,572

SHARE-BASED COMPENSATION - 2016 Global Incentive Plan (Details)			1 Months Ended				12 Months Ended
	Oct. 19, 2018 CNY (¥)	Jun. 08, 2018 CNY (¥)	Oct. 31, 2018 CNY (¥) director shares	Sep. 30, 2018 $ / shares shares	Mar. 31, 2018 shares	Jan. 31, 2016 $ / shares shares	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2018 CNY (¥) shares	Dec. 31, 2017 $ / shares	Dec. 31, 2017 CNY (¥) shares	Dec. 31, 2016 $ / shares	Dec. 31, 2016 CNY (¥)	Dec. 31, 2018 CNY (¥) shares
Number of Shares
Granted (in shares) \| shares				705,196
Valuation of options granted
Weighted average grant date fair value							$ 2.11		$ 0.86		$ 0.56
Research and development expenses
Valuation of options granted
Total share-based compensation expenses \| ¥	¥ 8,935,076
General and administrative expenses
Valuation of options granted
Total share-based compensation expenses \| ¥	¥ 10,535,229	¥ 33,537,572
Restricted share units
SHARE-BASED COMPENSATION
Vesting percentage			50.00%
Number of Shares
Granted (in shares) \| shares			100,000
Valuation of options granted
Total share-based compensation expenses \| ¥			¥ 375,123
Unrecognized compensation expense \| ¥			¥ 2,597,292
Expenses expected to be recognized over a weighted average period			1 year 9 months
Number of independent directors \| director			5
Amended 2016 Plan
SHARE-BASED COMPENSATION
Expiration period					10 years
Number of Shares
Outstanding at beginning of period (in shares) \| shares							4,265,750	4,265,750
Granted (in shares) \| shares					5,861,480		1,215,696	1,215,696
Forfeited (in shares) \| shares							(167,200)	(167,200)
Outstanding at end of period (in shares) \| shares							5,314,246	5,314,246		4,265,750
Exercisable at end of period (in shares) \| shares							2,059,200						2,059,200
Weighted Average Exercise Price
Outstanding at beginning of period (in dollars per share)							$ 0.20
Granted (in dollars per share)							0.08
Forfeited (in dollars per share)							0.20
Outstanding at end of period (in dollars per share)							0.17		0.20
Options exercisable at end of period (in dollars per share)							$ 0.20
Weighted Average Contractual Term
Outstanding at end of period							0 years	0 years
Options vested or expected to vest at end of period							0 years	0 years
Aggregate Intrinsic Value
Outstanding at end of period \| $							$ 17,644,761
Options exercisable at end of period \| $							$ 6,795,360
Valuation of options granted
Risk-free rate of return, Minimum							2.78%	2.78%		2.25%		1.52%
Risk-free rate of return, Maximum							3.13%	3.13%		2.48%		1.95%
Volatility, Minimum							49.90%	49.90%		51.70%		54.80%
Volatility, Maximum							50.90%	50.90%		54.40%		56.50%
Expected dividend yield							0.00%	0.00%		0.00%		0.00%
Exercise multiple							$ 2.2		2.2		2.2
Fair value of underlying ordinary share, Minimum							2.05		0.44		0.44
Fair value of underlying ordinary share, Maximum							$ 4.10		$ 1.22		$ 0.80
Expected term							10 years	10 years		10 years		10 years
Total share-based compensation expenses \| ¥								¥ 5,719,953		¥ 3,296,155		¥ 2,720,097
Unrecognized compensation expense \| ¥													¥ 21,953,326
Expenses expected to be recognized over a weighted average period							3 years 3 months 29 days	3 years 3 months 29 days
Amended 2016 Plan \| Cost of revenues
Valuation of options granted
Total share-based compensation expenses \| ¥								¥ 246,947		253,545		220,226
Amended 2016 Plan \| Selling and marketing expenses
Valuation of options granted
Total share-based compensation expenses \| ¥								2,124,728		1,611,160		1,377,422
Amended 2016 Plan \| Research and development expenses
Valuation of options granted
Total share-based compensation expenses \| ¥								955,538		832,782		708,847
Amended 2016 Plan \| General and administrative expenses
Valuation of options granted
Total share-based compensation expenses \| ¥								¥ 2,392,740		598,668		413,602
Amended 2016 Plan \| Restricted share units
Number of Shares
Granted (in shares) \| shares							100,000	100,000
Outstanding at end of period (in shares) \| shares							100,000	100,000
Weighted Average Exercise Price
Granted (in dollars per share)							$ 4.33
Outstanding at end of period (in dollars per share)							$ 4.33
2018 Plan
SHARE-BASED COMPENSATION
Percentage of increase in total number of ordinary shares issued and outstanding				1.50%
Number of Shares
Granted (in shares) \| shares				6,733,703
Valuation of options granted
Total share-based compensation expenses							$ 265,874,927			62,527,098		78,304,903
2018 Plan \| Cost of revenues
Valuation of options granted
Total share-based compensation expenses							246,947			253,545		220,226
2018 Plan \| Selling and marketing expenses
Valuation of options granted
Total share-based compensation expenses							2,124,728			1,611,160		1,377,422
2018 Plan \| Research and development expenses
Valuation of options granted
Total share-based compensation expenses							52,864,313			13,878,635		13,530,062
2018 Plan \| General and administrative expenses
Valuation of options granted
Total share-based compensation expenses							$ 210,638,939			¥ 46,783,758		¥ 63,177,193
Tranche One \| Amended 2016 Plan
SHARE-BASED COMPENSATION
Vesting percentage						40.00%
Vesting period						3 years
Number of Shares
Granted (in shares) \| shares						4,776,250
Weighted Average Exercise Price
Granted (in dollars per share)						$ 0.20
Tranche Two \| Amended 2016 Plan
SHARE-BASED COMPENSATION
Vesting period				4 years
Number of Shares
Granted (in shares) \| shares				70,519
Weighted Average Exercise Price
Granted (in dollars per share)				$ 0

SHARE-BASED COMPENSATION - 2018 Share Incentive Plan (Details)			1 Months Ended	12 Months Ended
	Oct. 19, 2018 CNY (¥)	Jun. 08, 2018 CNY (¥)	Sep. 30, 2018 shares	Dec. 31, 2018 USD ($)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
SHARE-BASED COMPENSATION
Maximum aggregate number of ordinary shares available for issuance \| shares			705,196
Research and development expenses
SHARE-BASED COMPENSATION
Total share-based compensation expenses \| ¥	¥ 8,935,076
General and administrative expenses
SHARE-BASED COMPENSATION
Total share-based compensation expenses \| ¥	¥ 10,535,229	¥ 33,537,572
2018 Plan
SHARE-BASED COMPENSATION
Maximum aggregate number of ordinary shares available for issuance \| shares			6,733,703
Percentage of increase in total number of ordinary shares issued and outstanding			1.50%
Total share-based compensation expenses				$ 265,874,927	¥ 62,527,098	¥ 78,304,903
2018 Plan \| Cost of revenues
SHARE-BASED COMPENSATION
Total share-based compensation expenses				246,947	253,545	220,226
2018 Plan \| Selling and marketing expenses
SHARE-BASED COMPENSATION
Total share-based compensation expenses				2,124,728	1,611,160	1,377,422
2018 Plan \| Research and development expenses
SHARE-BASED COMPENSATION
Total share-based compensation expenses				52,864,313	13,878,635	13,530,062
2018 Plan \| General and administrative expenses
SHARE-BASED COMPENSATION
Total share-based compensation expenses				$ 210,638,939	¥ 46,783,758	¥ 63,177,193

FAIR VALUE MEASUREMENT - Fair value hierarchy for assets and liabilities (Details) - CNY (¥)	Dec. 31, 2018	Dec. 31, 2017
Fair value hierarchy for assets and liabilities measured at fair value on recurring basis
Short-term investments (Note 3)	¥ 120,241,425	¥ 85,187,718
Convertible loan (Note 11)		151,557,796
Level 2
Fair value hierarchy for assets and liabilities measured at fair value on recurring basis
Short-term investments (Note 3)	¥ 120,241,425	85,187,718
Level 3
Fair value hierarchy for assets and liabilities measured at fair value on recurring basis
Convertible loan (Note 11)		¥ 151,557,796

FAIR VALUE MEASUREMENT - Level 3 Reconciliation (Details) - CNY (¥)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Level 3 Reconciliation
Conversion to Series A-3 Preferred Shares	¥ (628,062,274)
Convertible Loan
Level 3 Reconciliation
Convertible loan-beginning of year	151,557,796	¥ 116,728,899	¥ 151,557,796
Issuance	115,808,672
Change in Fair Value		43,006,399	34,499,858
Conversion to Series A-3 Preferred Shares			(181,112,874)
Foreign Currency Translation Adjustment	920,227	(8,177,502)	(4,944,780)
Convertible loan-end of year	¥ 116,728,899	¥ 151,557,796	¥ 116,728,899

INCOME TAX (Details)	12 Months Ended
INCOME TAX (Details)	Dec. 31, 2018
Hong Kong SAR
INCOME TAX
Statutory income tax (as a percent)	16.50%
PRC
INCOME TAX
Statutory income tax (as a percent)	25.00%

INCOME TAX - Components of (loss)/income before income taxes and withholding tax on undistributed dividends (Details)	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
INCOME TAX
(Loss)/income before income taxes	$ (50,763,942)	¥ (349,027,476)	¥ (184,662,871)	¥ (232,720,922)
Current income tax expense		¥ 0	0	0
Withholding income tax rate	5.00%	5.00%
Percentage of ownership interests held by foreign investors (as a percent)	25.00%	25.00%
Cayman
INCOME TAX
(Loss)/income before income taxes		¥ (34,397,077)	(39,610,348)	(4,788,106)
Hong Kong SAR
INCOME TAX
(Loss)/income before income taxes		(4,507,360)	219,935	(645,109)
PRC, excluding Hong Kong SAR
INCOME TAX
(Loss)/income before income taxes		¥ (310,123,039)	¥ (145,272,458)	¥ (227,287,707)

INCOME TAX - Reconciliation of differences between PRC statutory income tax rate and effective income tax rate (Details) - CNY (¥)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of differences between PRC statutory income tax rate and effective income tax rate
Computed expected income tax expense	¥ (87,256,869)	¥ (46,165,718)	¥ (58,180,231)
Non-PRC entities not subject to income tax	9,726,109	9,847,603	1,358,304
Research and development expenses bonus deduction	(7,528,081)	(1,032,177)	(1,285,563)
Non-deductible share-based compensation expenses	66,374,951	15,631,775	19,576,226
Other non-deductible expenses	176,111	358,759	106,757
Change in valuation allowance	¥ 18,507,779	¥ 21,359,758	¥ 38,424,507

INCOME TAX - Deferred income tax assets (Details) - CNY (¥)	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Deferred income tax assets
Net operating loss carry forwards	¥ 74,657,570	¥ 63,106,433
Accrued warranty	12,218,071	7,662,170
Accrued payroll and social insurance	5,099,295	4,112,541
Deferred revenue	3,225,283	2,499,515
Advertising expense	2,955,152	1,834,909
Allowance for doubtful accounts	57,037	489,061
Less: Valuation allowance	¥ (98,212,408)	¥ (79,704,629)	¥ (58,344,871)	¥ (19,920,364)

INCOME TAX - Operating loss carry forwards (Details)	Dec. 31, 2018 CNY (¥)
INCOME TAX
Operating loss carry forwards, Total	¥ 298,630,280
Operating loss carry forwards, 2020	70,541,275
Operating loss carry forwards, 2021	125,990,557
Operating loss carry forwards, 2022	50,592,424
Operating loss carry forwards, 2023	¥ 51,506,024

INCOME TAX - PRC Tax Administration and Collection Law (Details)	12 Months Ended
	Dec. 31, 2018 CNY (¥)
INCOME TAX
Period of statute of limitations, if the underpayment of taxes is due to computational errors made by the taxpayer or the withholding agent	3 years
Period of statute of limitations, if the underpayment is more than RMB 100,000	5 years
Minimum amount of underpayment of taxes for statute of limitations to be extended to five years	¥ 100,000
Period of statute of limitations for transfer pricing issues	10 years

NET LOSS PER ORDINARY SHARE - Basic and diluted net loss per share computation (Details)	12 Months Ended
	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2018 CNY (¥) ¥ / shares shares	Dec. 31, 2017 CNY (¥) ¥ / shares shares	Dec. 31, 2016 CNY (¥) ¥ / shares shares
Numerator:
Net loss attributable to ordinary shareholders	$ (50,763,942)	¥ (349,027,476)	¥ (184,662,871)	¥ (232,720,922)
Numerator for basic and diluted net loss per share calculation	$ (50,763,942)	¥ (349,027,476)	¥ (184,662,871)	¥ (232,720,922)
Denominator:
Weighted average number of shares outstanding used in computing net loss per share	65,834,876	65,834,876	26,295,181	10,414,325
Net loss per share attributable to ordinary shareholders
Basic and diluted \| (per share)	$ (0.77)	¥ (5.30)	¥ (7.02)	¥ (22.35)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details

NET LOSS PER ORDINARY SHARE - Antidilutive securities (Details) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Share options
Antidilutive securities
Antidilutive securities	5,314,246	4,265,750
Restricted share units
Antidilutive securities
Antidilutive securities	100,000
Restricted ordinary shares
Antidilutive securities
Antidilutive securities		32,689,010
Series Seed Convertible Preferred Shares
Antidilutive securities
Antidilutive securities		30,000,000
Series A Preferred Shares
Antidilutive securities
Antidilutive securities		25,278,350
Convertible Loan
Antidilutive securities
Antidilutive securities		10,119,329

REVENUE INFORMATION - Disaggregation of revenue (Details)	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
REVENUE INFORMATION
Net revenues	$ 214,934,376	¥ 1,477,781,304	¥ 769,368,001	¥ 354,810,048
Electronic scooter sales
REVENUE INFORMATION
Net revenues		1,370,522,269	709,595,841	337,920,673
Accessory and Spare parts sales
REVENUE INFORMATION
Net revenues		91,373,179	49,159,080	14,920,309
Service revenues
REVENUE INFORMATION
Net revenues		¥ 15,885,856	¥ 10,613,080	¥ 1,969,066

REVENUE INFORMATION - Revenues based on geographic areas (Details)	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
Disaggregation of Revenue [Line Items]
Net revenues	$ 214,934,376	¥ 1,477,781,304	¥ 769,368,001	¥ 354,810,048
PRC
Disaggregation of Revenue [Line Items]
Net revenues		1,318,657,227	731,423,647	353,041,492
Europe
Disaggregation of Revenue [Line Items]
Net revenues		148,963,330	36,257,165	1,118,230
Others
Disaggregation of Revenue [Line Items]
Net revenues		¥ 10,160,747	¥ 1,687,189	¥ 650,326

COMMITMENTS AND CONTINGENCIES (Details) - CNY (¥)	12 Months Ended
COMMITMENTS AND CONTINGENCIES (Details) - CNY (¥)	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
COMMITMENTS AND CONTINGENCIES
Rental expenses	¥ 7,306,686	¥ 4,896,922	¥ 3,981,515
Future minimum lease commitments
2019	6,943,633
2020	3,333,014
2021	¥ 1,293,531

SUBSEQUENT EVENTS (Details)		1 Months Ended
SUBSEQUENT EVENTS (Details)	Jan. 23, 2019 CNY (¥)	Nov. 30, 2017 USD ($)	Mar. 15, 2019 USD ($)	Dec. 31, 2018 CNY (¥)	Nov. 30, 2018 USD ($)	Dec. 31, 2017 CNY (¥)
SPD Silicon Valley Bank loan
SUBSEQUENT EVENTS
Debt term		1 year
Short-term bank borrowing				¥ 60,000,000		¥ 60,000,000
Interest rate (in percent)				4.35%		4.35%
Deposits remained at the bank and restricted \| $		$ 10,000,000			$ 10,000,000
Subsequent Event \| SPD Silicon Valley Bank loan
SUBSEQUENT EVENTS
Interest rate (in percent)			4.35%
Deposits remained at the bank and restricted \| $			$ 10,000,000
Subsequent Event \| Beijing Niudian \| Bank of Ningbo
SUBSEQUENT EVENTS
Debt term	1 year
Short-term bank borrowing	¥ 28,500,000
Interest rate (in percent)	5.32%
Guaranty loan by restricted cash	¥ 30,000,000

PARENT COMPANY ONLY CONDENSED FINANCIAL INFORMATION - Condensed Balance Sheets (Details)	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)	Dec. 31, 2015 CNY (¥)
Current assets
Cash	$ 82,766,285	¥ 569,059,591	¥ 111,996,325
Term deposit	3,992,824	27,452,663
Restricted cash-current	26,072,680	179,262,714	104,547,200
Prepayments and other current assets	3,915,345	26,919,954	7,349,583
Total current assets	162,859,922	1,119,743,397	407,688,903
Non-current assets
Restricted cash-non current			65,342,000
Total non-current assets	9,527,803	65,508,402	95,942,674
Total assets	172,387,725	1,185,251,799	503,631,577
Current liabilities
Convertible loan			151,557,796
Accrued expenses and other current liabilities	19,516,258	134,184,026	75,412,869
Total liabilities	89,425,461	614,844,753	591,022,538
MEZZANINE EQUITY
Total mezzanine equity			237,844,515	¥ 252,506,413	¥ 125,975,835
SHAREHOLDERS' (DEFICIT) / EQUITY:
Ordinary shares			39,948
Additional paid-in capital	249,797,622	1,717,483,548	440,265,896
Accumulated other comprehensive income/(loss)	(3,314,220)	(22,786,922)	5,596,238
Accumulated deficit	(163,535,094)	(1,124,385,539)	(771,155,994)
Total shareholders' (deficit)/equity	82,962,264	570,407,046	(325,235,476)	(213,194,529)	(56,195,156)
Total liabilities, mezzanine equity and shareholders' (deficit)/equity	172,387,725	1,185,251,799	503,631,577
Series A1 Redeemable Convertible Preferred Shares
MEZZANINE EQUITY
Total mezzanine equity			130,684,003	138,740,003	129,872,003
Series A-2 Redeemable Convertible Preferred Shares
MEZZANINE EQUITY
Total mezzanine equity			39,205,192	41,621,992	¥ 38,961,592
Series A-3 Redeemable Convertible Preferred Shares
MEZZANINE EQUITY
Total mezzanine equity			67,955,320	¥ 72,144,418
Series Seed Convertible Preferred Shares
SHAREHOLDERS' (DEFICIT) / EQUITY:
Series Seed Convertible Preferred Shares			18,436
Class A Ordinary Shares
SHAREHOLDERS' (DEFICIT) / EQUITY:
Ordinary shares	12,089	83,120
Class B Ordinary Shares
SHAREHOLDERS' (DEFICIT) / EQUITY:
Ordinary shares	$ 1,867	12,839
Parent Company \| Reportable Legal Entities
Current assets
Cash		149,901,311	39,678,102
Term deposit		27,452,663
Restricted cash-current		124,357,114	52,273,600
Amount due from subsidiaries and consolidated VIE and VIE's subsidiaries		405,843,735	53,490,993
Prepayments and other current assets		3,707,403
Total current assets		711,262,226	145,442,695
Non-current assets
Restricted cash-non current			65,342,000
Total non-current assets			65,342,000
Total assets		711,262,226	210,784,695
Current liabilities
Convertible loan			151,557,796
Amount due to subsidiaries and consolidated VIE and VIE's subsidiaries		4,262,270
Accrued expenses and other current liabilities		7,593,082
Total liabilities		11,855,352	151,557,796
MEZZANINE EQUITY
Total mezzanine equity			237,844,515
SHAREHOLDERS' (DEFICIT) / EQUITY:
Ordinary shares			39,948
Additional paid-in capital		1,717,483,548	440,265,896
Accumulated other comprehensive income/(loss)		(25,394,429)	3,281,862
Accumulated deficit		(992,778,204)	(622,223,758)
Total shareholders' (deficit)/equity		699,406,874	(178,617,616)
Total liabilities, mezzanine equity and shareholders' (deficit)/equity		711,262,226	210,784,695
Parent Company \| Reportable Legal Entities \| Series A1 Redeemable Convertible Preferred Shares
MEZZANINE EQUITY
Total mezzanine equity			130,684,003
Parent Company \| Reportable Legal Entities \| Series A-2 Redeemable Convertible Preferred Shares
MEZZANINE EQUITY
Total mezzanine equity			39,205,192
Parent Company \| Reportable Legal Entities \| Series A-3 Redeemable Convertible Preferred Shares
MEZZANINE EQUITY
Total mezzanine equity			67,955,320
Parent Company \| Reportable Legal Entities \| Series Seed Convertible Preferred Shares
SHAREHOLDERS' (DEFICIT) / EQUITY:
Series Seed Convertible Preferred Shares			¥ 18,436
Parent Company \| Reportable Legal Entities \| Class A Ordinary Shares
SHAREHOLDERS' (DEFICIT) / EQUITY:
Ordinary shares		83,120
Parent Company \| Reportable Legal Entities \| Class B Ordinary Shares
SHAREHOLDERS' (DEFICIT) / EQUITY:
Ordinary shares		¥ 12,839

PARENT COMPANY ONLY CONDENSED FINANCIAL INFORMATION - Condensed Statements of Results of Operations (Details)	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
Condensed Statement of Income Captions [Line Items]
Changes in fair value of a convertible loan	$ (5,017,796)	¥ (34,499,858)	¥ (43,006,399)
Interest income	436,157	2,998,796	1,006,972	¥ 660,601
Foreign currency exchange (losses)/gain	239,426	1,646,173	1,612,766	(6,279,783)
Loss before income taxes	(50,763,942)	(349,027,476)	(184,662,871)	(232,720,922)
Net loss	$ (50,763,942)	(349,027,476)	(184,662,871)	(232,720,922)
Parent Company \| Reportable Legal Entities
Condensed Statement of Income Captions [Line Items]
Total operating expenses		(1,908,246)	(163,640)	(393,856)
Changes in fair value of a convertible loan		(34,499,858)	(43,006,399)
Share of losses from subsidiaries, VIE and VIE's subsidiaries		(331,955,300)	(62,527,098)	(198,821,537)
Interest income		2,011,390	366,795	150,594
Foreign currency exchange (losses)/gain		(364)	3,192,896	(4,544,844)
Loss before income taxes		(366,352,378)	(102,137,446)	(203,609,643)
Net loss		¥ (366,352,378)	¥ (102,137,446)	¥ (203,609,643)

PARENT COMPANY ONLY CONDENSED FINANCIAL INFORMATION - Condensed statements of cash flows (Details)	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
Condensed statements of cash flows
Net cash (used in)/provided by operating activities	$ 1,131,460	¥ 7,779,366	¥ 80,063,278	¥ (123,053,734)
Net cash used in investing activities	(15,066,491)	(103,589,651)	(55,928,949)	(59,949,934)
Net cash provided by financing activities	80,777,047	555,382,588	2,414,710	225,011,777
Effect of foreign currency exchange rate changes on cash	(364,921)	(2,509,037)	(5,673,424)	2,061,790
Net increase in cash	66,477,095	457,063,266	20,875,615	44,069,899
Cash at the beginning of the year	16,289,190	111,996,325	91,120,710	47,050,811
Cash at the end of the year	$ 82,766,285	569,059,591	111,996,325	91,120,710
Reportable Legal Entities \| Parent Company
Condensed statements of cash flows
Net cash (used in)/provided by operating activities		(352,222,011)	12,825,090	(76,650,478)
Net cash used in investing activities		(19,902,073)
Net cash provided by financing activities		481,123,035		104,354,252
Effect of foreign currency exchange rate changes on cash		1,224,258	(1,889,261)	(498,905)
Net increase in cash		110,223,209	10,935,829	27,204,869
Cash at the beginning of the year		39,678,102	28,742,273	1,537,404
Cash at the end of the year		¥ 149,901,311	¥ 39,678,102	¥ 28,742,273

CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical)	12 Months Ended
CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical)	Dec. 31, 2018 CNY (¥)
CONSOLIDATED STATEMENTS OF CASH FLOWS
Underwriting commissions and discounts for issuance of Class A Ordinary Shares upon IPO	¥ 30,599,667

RELATED PARTY TRANSACTIONS	12 Months Ended
RELATED PARTY TRANSACTIONS	Dec. 31, 2018
RELATED PARTY TRANSACTIONS
RELATED PARTY TRANSACTIONS	21. RELATED PARTY TRANSACTIONS Mr. Yi’nan Li, the founder and a board member of the Company until June 8, 2018 and Mr. Changlong Sheng, a shareholder of the Company, provide joint liability guaranty for the 2017 BOC Loan, the 2018 BOC Loan and the 2019 BOC Loan (Note 10) borrowed by Jiangsu Xiaoniu.

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details)	Dec. 31, 2018 ¥ / $
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Convenience translation rate (in RMB/USD)	6.8755

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Selling and Marketing Expenses, Employee Benefits (Details) - CNY (¥)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Advertising expenses	¥ 76,791,991	¥ 28,345,034	¥ 51,170,420
Employee social benefits included as expenses	¥ 15,544,106	¥ 13,705,669	¥ 12,652,658

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Segment Reporting (Details)	12 Months Ended
	Dec. 31, 2018 segment
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Number of operating segment	1