Abstract: Aimed at the pollution source that polluted the environment of surface water and based on the soil conservation service(SCS) of runoff simulation,the correlativity between annual precipitation and runoff coefficient of different land use types was established,which was significant.Moreover,under the different rain intensities,the rainfall process in urban sewage outfall of typical demonstration zone was monitored.And the average pollutant concentration of urban runoff in representative city was obtained,which provided the gist to research the pollution load in urban runoff.Sequentially,the gross of urban runoff pollution load in Liaoning province was evaluated.