Soil erodibility of seven soils located in ziyang soil and water conservation fieldstation ofsichuan Academy of Agricultural sciences,ziyang,was studied under rainfall simulator.The resultshows:1.the soil erodibility of seven soils is yellow earthbrown purple soilred brown purplesoilgrey alluvial soilred purple soilyellow red purple soildarkbrown purple soil;2.thereis a significant linear relationship between runoff and rainfall duration,soil loss and rainfall duration, runoff and soil loss for seven soils,and Clear non linear relationship between soil moisture contentand runoff starting time for six soils.