Abstract：A new method，particle swarm optimization(PSO) algorithm，is adopted to locate the non-circular critical slip surfaces of slopes. These slip surfaces are verified and refined frequently by PSO algorithm and tend gradually to the critical slip surface，and simultaneously their safety factors decrease towards the global minimum safety factors. The critical slip surface and its corresponding global minimum safety factor can be obtained within limited iterations. PSO algorithm can achieve a good balance between a global search and a local refinement；and it can solve the problem of falling into local minima，which happens in most of the regular optimization methods. At the same time，it shows great efficiency. Furthermore，PSO algorithm can be easily incorporated with the traditional limit equilibrium methods as well as the finite element method for slope stability analysis. A numerical example is analyzed to show the effectiveness and efficiency of the proposed method.
