Abstract: In this paper a three dimensional limit equilibrium method is presented for stability assessment of the slope with distinct spatial features. Four types of sliding surfaces can be used in this method, namely, the known discontinuity, sphere, rotational ellipsoid, and composite surface. The user of the program can easily select the possible sliding surface with the help of his experience. Calculation can be conducted on a series of sliding directions possible from the engineering viewpoint. Seepage and seismic forces and other factors are considered. An example of analysis of a reservoir bank slope displays that the proposed method is suitable for 3D treatment.