Abstract: In order to cognize the permeable property of the frozen silty clay spreading widely in permafrost regions on the Qinghai-Tibet Plateau, a series of laboratory tests are conducted to measure the hydraulic conductivities of the frozen silty clays with moisture content of 50% at temperatures from -0.6 to 0.1^oC. The results show that under the warm negative temperatures, the hydraulic conductivities of frozen silty clay are in the range of 8.22×10^-11~7.19×10^-9 cm/s. In addition, the hydraulic conductivity has a power function relationship with the soil temperature, and it grows more rapidly as the temperature gets closer to 0 ^oC. And the hydraulic conductivity expresses a rapid increase tendency with the increasing volumetric content of unfrozen water. The existence and measurability of the permeability in frozen soils indicate that consolidation may occur in warm frozen soils under external loads.