Abstract: The specimens of silty sand, standard sand and clay with different void ratios are prepared. By utilizing a multifunctional permeability test apparatus, a series of permeability tests are carried out under the conditions of pure soils and woven geotextiles covered with soils. The difference in hydraulic conductivity under these two conditions is analyzed by comparisons. The mechanism of seepage under the interaction between geotextile and soil is discussed. The results show that the woven geotextile has a slight suppression effect on the seepage of soil, resulting in the case that the hydraulic conductivity of the geotextile covered with soil is a bit lower than that of the soil. However, for the silty sand with a relatively large void ratio and a relatively high content of fine sands, loss of fine sand grains owing to passing through the voids of woven geotextile may take place under the actions of seepage. This will result in the case that the hydraulic conductivity of the geotextile covered with silty sand is a bit higher than that of the silty sand.