Abstract: Nonlinear FEM strength reduction is a slop stability analysis method which is widely cared in the geotechnical field. With the anti-shear parameters c- reduction, the nonlinear FEM model of rock slope reduced to instable status and the numerical non-convergence occurred simultaneously. And then the safety factor was obtained by c- reduction algorithm for which can be regarded as equal to stability factor . With a case study, the results of 2D analyses are analyzed, which matches the actual circumstance. The study results show that the stability safety factor of the rock slope can be obtained in a quick and effective way by using the finite element stress analysis method in combination with the finite element strength reduction method, which can provide certain basis for evaluation of rock slope stability.