The objective of the study describes the quantitative relationship of the spatial structure of urban underlying surface and rainfall infiltration rate.The rainfall simulator is designed to study the proportion,shape,evenness and separation of impervious patch influence on rainfall infiltration rate in the same initial condition.The results show that changing the proportion,shape,evenness and separation of impervious patch causes different rainfall infiltration yield.Factors of affecting rainfall infiltration rate of urban underlying surface spatial structure,proportion of impervious patch have great contribution to the rainfall infiltration rate.The effect of shape,evenness and separation of impervious patch is less than the contribution of the proportion of impervious patch.However,the effect of shape,evenness and separation of impervious patch on rainfall infiltration rate is also very prominent.In urban landscape,arrange the shape,evenness and separation of impervious patch rationally will be very effective on controlling urban rainfall infiltration yield.