By monitoring the quality of the roof rainwater gathered in Shanghai and analyzing the main influential factors as well as the pollution level,it is found that roof material,rainfall duration,rainfall intensity and volume are important influential factors affecting the quality of runoff from roofs.On the basis of quality characteristics of runoff from roofs,physicochemical and ecological treatment and utilization methods and processes fit for polluted rainwater are proposed.It lays the foundation of utilization of the urban rainwater resources.