Based on data of groundwater pollution survey and historical observation, this paper revealed the variation characteristics and its influencing factors of groundwater levels and quality in Lanzhou. Urban sewage discharge, water storage construction, agricultural irrigation and other factors increase the vertical infiltration recharge of groundwater which caused groundwater level to rise especially in Xigu district. Affected by groundwater exploitation, the water source regions formed a large area of groundwater drawdown funnel, the water level dropped significantly. There are many factors affecting groundwater quality in Lanzhou city.The change of land use type caused the increase of pollution sources, the disposal method of urban waste and the groundwater drawdown are important factors which caused deterioration of groundwater quality directly or indirectly.The indexes of groundwater such as TH, NO-3, F- and organic compounds show an increasing trend in old city and industrial zone.The situation of pollution is grim.