SCS model is adopted in this paper to simulate surface runoff' for Lake Fuxian catchment. The modelconsiders the spatial diversities of the Iand surface via dividing the catchment into a number of hydrological responseunits(HRU) based on diH'erent landuses and soil types. The surface runoff for each HRU is calculated and the totat surface runoff into the lake is modeled. CN values of the SCS model are calibrated场matching the modeled resulfa with the observed ones for the gauged river catchments of Liangwanghe and Dajiyugou. The model is then opplied to other ungauged areas of Lake Fuxian catchment after making slope corrections of the CN values. The modelindicates that the total surface runoff is 174 million ms for a one-year period of March 2005 to February 2006,withan average runoff cae}cient of 0. 395. The model is believed to be helpful in guiding further field observations. Themodeled results are also useful in constructing more detailed hydrological models as the next step, and in calculating mass of pollutants loaded to the lake.