Abstract: Thermal diffusivities of different texture soils were calculated according to measured temperature data and different solutions of heat flow equation in non-steady condition, and then, the relationships between thermal conductivities and water content for three textures were analyzed. The results have shown that to certain soil, the relationships between thermal conductivities and water content can be expressed by power function. Meanwhile, the particle content of sand, silt, and clay plays different roles in soil thermal properties, soil thermal parameters can be quantified by soil water suction, and soil thermal conductivity can be expressed by power function of soil salt concentration.