Abstract: Water resources is considered as a key of the development in Northwest China,so its characteristic must be thought enough and accurately.The water resource data in Northwest China is analyzed,which indicate that: (1) the runoff of endorheic drainage is mainly formed in mountain regions,dissipated at basin or plain front of mountain,and supplied by the rainfall,snowfall,glacier and groundwater; (2) Glacier and snowfall play an important part in adjustment of surface water; (3) transformation relationship between rainfall,surface water and groundwater is notable,and (4) The water resources balance of endorheic drainage is easily influenced by the human actions.