ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES (Tables)
 12 Months Ended
Dec. 31, 2017
ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES [Abstract]  
Schedule of Accrued Expenses and Other Current Liabilities
 
 
December 31,
 
 
 
2016
 
2017
 
 
 
RMB
 
RMB
 
VAT and other tax payables
 
 
29,995
 
 
31,623
 
Accrued payroll and employee benefits
 
 
59,512
 
 
88,713
 
Others
 
 
28,360
 
 
64,310
 
Total
 
 
117,867
 
 
184,646