The hydrodynamic process of soil water erosion was systemically simulated in the study by artificial precipitation experiments with treatments of two slopes(20° and 25°) and four rainfall intensities.The relationship between sediment yield and its impact factors was also studied using gray correlation analysis.The results show that rainfall intensity had the highest correlation coefficient with surface erosion sediment yield.Stream power was the factor with the second highest coefficient.Surface erosion sediment yield was therefore described by rainfall intensity and stream power with established regression equation.