Abstract: Dual evaluation system of landslide stability, which couples safety factor and reliability,was introduced in this paper.The stochastic analysis method was adopted to analyse the distribution of safety factor and the failure probabilities P_f of most likely factor was decided,therefore the reliable safety factor,based on safety factor and reliability,was obtained to appraise the landslide stability.From limit state of reduced safety factor,choosing canonical different maximum possible safety factors and their corresponding critical failure probabilities to build the division chart of landslide stability.The results of research example have shown that dual system based on stochastic analysis was a feasible method and could give us a more precise and objective evaluation of landslide stability.