Abstract: With the rapid economic and social development,China is now in a period of rapid development of urbanization,which is confronted with a lot of acute problems for us to carefully study.Some impacts caused by urbanization such as precipitation and extreme storm,runoff generation and flow concentration in river basin,flood,demand and water supply and water resources protection,water quality and water environment,and water ecosystem are analyzed in this study.Based on the analysis of urban hydrologic effects,key problems on which the urban hydrology research is focusing are presented,such as the cause analysis of urban extreme storm,the calculation method for urban storm with flood,and the methods and key technology applied to rainwater and flood resources utilization,from the point of view of subject development and application.