Warm frozen soil refers to the frozen soil in the temperature range with severe phase changes. The term of warm frozen soil is usually used for describing frozen soil in relatively higher temperature blow 0 ℃. As a result of the temperature range with severe phase changes, the proportion of ice to unfrozen water is extremely sensitive to temperature change. Therefore, warm frozen soil is prone to considerable variation in physic-mechanical properties. Based on documents on physic-mechanical properties of warm frozen soil, the definition and temperature boundary of warm frozen soil are reviewed in this research. It is revealed that unfrozen water has a tremendous impact on the physic-mechanical properties of warm frozen soil, and pointed out that to measure the pore water pressure in the warm frozen soil is meaningful and interesting. The general findings of recent researches are reviews in this research. The mechanical properties of warm frozen soil are summarized from three different respects, including strength characteristics, deformation properties and constitutive models. In order to provide theoretical basis for analysis of deformation and stability of foundations for various engineering projects in warm permafrost regions, further researches on the mechanism of deformation and proper constitutive model of warm frozen soil is around the corner.