Stability can be evaluated more reasonably by analysis of systematic reliability of rock slope with various sliding surfaces. Using nonlinear FEM, the possible sliding surfaces could be found by reducing rock strength, and a failure mode is defined that all the elements of the sliding surface are destroyed synchronously; According to Druker Prager yield rule and uniaxial tensile rule, the performance functions of elements are built, the reliability indexes and correlation coefficients are computed by response surface method and Monte Carlo method; Each failure mode is a parallel system consist of the elements of each sliding surface, so a stepping equivalent linear method was researched to calculate the reliability index of each failure modeFinally, the reliability index of the series system composed by all failure modes can be estimated by Ditlevsen narrow bound method. The reliability index gained from the above method can be applied to appraise slope stability. For example, the systematic reliability of a slope was analyzed, which shows the method is rational and feasible.
