Abstract:The computing method for the stability analysis of slopes composed of horizontal layers under seismic load is studied. According to the characteristics of such slopes,horizontal slice method (HSM) is developed and applied to search for the critical slip surface in combination with genetic algorithm (GA) which is of the capability of global convergence. The analysis results of some slopes by the proposed method and the comparisons between the proposed method and other ones show that the proposed method is accurate,reliable and able to find out the global optimal solution.