Abstract: The finite element c-tanФ reduction theory is applied to the slope stability analysis, which is using ANSYS finite element analysis software, based on Drucker-Prager yield criterion, using force and displacement convergence criteria as the damage criterion to carry out the slope stability analysis. When the reduction coefficient reaches to a certain value, the non-linear finite element calculation will not converge, the displacement of the sliding surface will mutation, slope, within a certain amplitude of the generalized shear strain gradient from its base to the top, so the slope had been destroyed, the previous reduction factor shall be the stability factor. In the paper, taking the Hancheng coal jointed rock slope for example, applying the c-tanФ, reduction theory to its stability analysis. The results show that the FEM and strength - reduction method is more convenient and reasonable in the analysis of rock slope stability. It can reflect the actual slope state, and give stability factors that are closer to the actual ones.