Abstract：The strength parameters of soil in slide zone are indispensable factors for stability evaluation and control design to a landslide. In this paper，the strength characteristics of soil in slide zone are analyzed，and the residual strength parameters and the restorative strength parameters of the soil in slide zone are discussed，too. The implication of the stability safety factor for landslide and the strength parameters of soil in slide zone is gotten clear through discussion about the definition of the stability safety factor for landslide. The method of determination of the strength parameters of soil in slide zone is proposed. Combined with the practice of Gushubao landslide，the strength parameters of soil in slide zone are determined.
