Abstract: The environmental change impacted by rapid urbanization is a hot topic to global environmental change. In this area, research on water environmental effects of urbanization focuses on water quality, water quantity change and hydrological process and feedback disturbance. This paper reviews the mechanism between water environment change and urbanization, and summarizes the research issues we have face in this area, the methods we need, and how water environmental change responds to urban impervious surface. We also discuss the problems in the research of water environmental effects of urban impervious surface. Obviously, urbanization often directly changes natural land cover to impervious surface, but how to link urban land cover change with hydrological process and water quality is still a critical problem. The index of impervious surface area (ISA) was used to characterize land cover in urban area, and was a hot landscape indicator used to combine water environmental effects and urbanization processes. This paper indicates that the impacts of impervious surface on urban hydrology are mainly in two aspects. One is that it can increase the ratio of runoff and the amount of precipitation in a rainfall process in a short period, and the other is that it also can subsequently increase the higher runoff peaks and total volume of runoff in receiving waters and decrease the lag times in a long period. Changing natural land cover to impervious surface cover can obviously increase non-point pollution loadings and degrade water quality. In many urban areas, we depend on urban hydrological and water quality monitoring to link the relationship, and use urban hydrological and water quality model to simulate the impacts. However, the mechanism of impervious surface impact on urban water environment is still not clear. To solve this critical problem needs to know the impacting mechanism of non-point pollution loadings and to develop hydrological and water quality model suitable for urban areas. Overall, ISA is relatively simple for land planner and water quality administrator to use. This research indicates that ISA will be an important indicator to study water environmental effects of urbanization, and can also improve the modelling methods.