Based on the measured data obtained from Anxi, the Curves of the orifical runoff precipitation have been established on various slopes. The results show that the coefficient of surface runoff is below 5% and subsurface and underground flow would be dominant factor to make the flood on the slopes with good vegetation cover, and on the undisturbed bare slopes the coefficient is over 45% and the surface flow would be determinant to form the flood. The relationship between the precipitation loss and intensity f=aib have been set up on various slopes, and the curves of infiltration process f=ae-bt also have been simulated on the basis of analyzing to the process curves of precipitation and runoff. It is point that a would be main influenced by precipitation intensity and the advanced rainfall, and b would be determined by advanced rainfall.