INCOME TAX EXPENSE (Details) ¥ in Thousands, $ in Thousands	12 Months Ended
Dec. 31, 2022 CNY (¥)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 CNY (¥)	Dec. 31, 2020 CNY (¥)
Income Taxes
Provision for income taxes	¥ 0	$ 0	¥ 0	¥ 0
Hong Kong
Income Taxes
Provision for income taxes	¥ 0
Reconciliation between the effective income tax rate and the PRC statutory income tax rate (as a percent)
Statutory tax rate	16.50%	16.50%
PRC
Income Taxes
Preferential tax rate	15.00%	15.00%
Reconciliation between the effective income tax rate and the PRC statutory income tax rate (as a percent)
Statutory tax rate	25.00%	25.00%	25.00%
Tax effect of other expenses that are not deductible in determining taxable profit	(1.00%)	(1.00%)	(2.00%)
Effect of enacted tax rate change	2.00%	2.00%	2.00%
Effect of change in valuation allowance	(26.00%)	(26.00%)	(25.00%)
Effective tax rate	0.00%	0.00%	0.00%

Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Topic 740
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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to changes in the valuation allowance for deferred tax assets.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Percentage of domestic federal statutory tax rate for High and New Technology Enterprises applicable to pretax income (loss).

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