Abstract: The permeability characteristic of soils reflects their permeable capability, and it is an important parameter of water erosion models and used to asses the effect of soil erosion as an important index. The tests on the permeability of the typical sandy clayey purple soils in Chongqing area are performed by the multifunction triaxial apparatus different rainfall intensities and soil-covering depths in nature, and the influence laws of seepage pressure, confining pressure and geostatic stress on the permeability characteristics of soils are studied. The results show that the permeability coefficient of sandy clayey purple soils under different seepage pressures have the same order of magnitude. The confining pressure has a significant effect on the permeability coefficient of the soils, but as the confining pressure gradually increases, the decreasing gradient of permeability coefficient of soils gradually decreases. With the increase of geostatic stress, the permeability coefficient of soils decreases. The smaller the confining pressure, the more obvious the effect of geostatic stress. With the increase of soil-covering depth, the permeability coefficient of sandy clayey purple soils decreases rapidly. This research may provide reference for treatment of foundation, analysis of landslide mechanism, design of soil erosion control and so on.