Abstract: Designing and analyzing the rock-soil slope with strain-softening behaviors according to the peak strength tends to cause potential safety hazards, while that according to the residual strength tends to increase costs. The stability analysis methods for slopes considering strain-softening behaviors are of great significance. Based on the strain-softening constitutive relation, the progressive destruction of a slope is simulated in FLAC first. Then the slip surface is determined by the maximum shear strain increment. The vector sum method for stability analysis of the strain-softening slope is accomplished by Matlab based on the temporal-spatial distribution of strength parameters on the slip surface. The equivalent cohesion and internal friction angle are extracted from the spatial distribution of strength parameters of the slip surface. The limit equilibrium method is implemented to analyze variation of the slip surface and safety factor during the progressive destruction to supplement the drawback of the vector sum method. The results of the two methods for the stability analysis of strain-softening slopes are compared, and their reasonability and reliability are validated. The two methods show a complementary relationship in solving the stability problem of strain-softening slopes.