Abstract：At present，the methods of analyzing the stability of slope under earthquake are not accurate and reasonable because of some limitations．Based on the real dynamic tensile—shear failure mechanism of slope ．the paper proposes dynmnic analysis of strength reduction FEM (finite element method )and takes the reduction of shear strength parameters and tensile strength param eters into consideration．And it comprehensively takes the transfixion of the failure surface，the non—convergence of calculation and mutation of displacement as the criterion of dynamic instabihty and failure of the slope．The stYength reduction factor under limit state is regarded as the dynamic safety factor ofthe slope under earthquake efect and its advantages
are introduced．Finally，the method is applied in the seismic design of anchors supporting and anti·slide pile supporting of the slope．Calculation exam ples show that the application of dynamic analysis of strength reduction is feasible in the seismic design of slope engineering，which can consider dynamic interaction of supporting structure and rock—soil mass．Owing to its preciseness and great advantages，it is a new method in the seismic design of slope supporting