Abstract: Till now there are few studies for several influence factors and corresponding quantitative relations about rainfall and infiltration. Based on experiments of artificial precipitation simulations with vegetation mulches on slope land, the influences of some main factors on precipitation and infiltration regularities, including vegetation coverage, rainfall intensity and soil texture, etc, were analyzed. Results indicate that as the other conditions are fixed, the larger the grassland coverage, the higher the initial and the steady infiltration rates, and the larger the infiltration supplement coefficients. As the other conditions are fixed, the larger the rainfall intensities, the higher the initial and the steady infiltration rates, and the larger the accumulative infiltration as well as the infiltration supplement coefficients. Under the same conditions, the infiltration capacities of Huangmian soil is better than that of Lou soil. The infiltration rate is two-factor functions of both rainfall time and grassland coverage at different rainfall intensities for Huangmian soil. The infiltration rate and the accumulative infiltration are both two-factor functions of time and grassland coverage for Lou soil. The infiltration supplement coefficient is both two-factor function of grassland coverage and rainfall intensities for Huangmian soil.