Numerical investigations were carried out to determine the coupled heat transfer of water saturated porous media with a two phase closed thermosyphon for soil freezing, and to examine the characteristics of the freezing heat transfer in the water saturated porous media. The whole control volume includes the thermosyphon and the porous media. The two dimensional governing equations for the water saturated porous media are used. The conjugation of heat transfer between the thermosyphon and porous media is reflected through thermal balance between the thermosyphon and the porous media. The finite difference method was used to solve the two|dimensional governing equation for the water saturated porous media and the heat transfer characteristics of the thermosyphon, obtain the flow fields and the temperature distributions in the soil. This paper deals mainly with the effect of some factors (such as soil properties, climate and thermosyphon dimensions) on the heat transfer rate of the thermosyphon and the growth of the freezing front. The predictions of the present study agree well with the measured data. Numerical investigations were carried out to determine the coupled heat transfer of water saturated porous media with a two phase closed thermosyphon for soil freezing, and to examine the characteristics of the freezing heat transfer in the water saturated porous media. The whole control volume includes the thermosyphon The two dimensional governing equations for the water saturated porous media are used. The conjugation of heat transfer between the thermosyphon and porous media is reflected through thermal balance between the thermosyphon and the porous media. The finite difference method was used to solve the two | dimensional governing equation for the water saturated porous media and the heat transfer characteristics of the thermosyphon, obtain the flow fields and the temperature distributions in the soil. This paper deals mainly with the effect of some factors (such as soil properties, climate and thermosyphon dimensions) on the heat transfer rate of the thermosyphon and the growth of the freezing front. The predictions of the present study agree well with the measured data.