Abstract：Horizontal earthquake acceleration is used for slope risk analysis，and the relationship between the dynamical safety factors and corresponding static safety factors is obtained. The reliability of slope is expressed with the safety factor. The mathematic formulation of the slope failure probability is deduced with stochastic earthquake acceleration. In the case of a slope in the south-north water transfer project(SNWTP)，calculation results show that safety factor with the stochastic earthquake is 25% smaller than that without earthquake. It is clear that the influence of the earthquake is notable.
