Abstract: As one type of rock slope failures,toppling could be correctly simulated only if deformation and stress,failure growth,contacts and movements of blocks were well taken into account.The numerical manifold method could be used for this purpose.The fundamental principles of manifold method,the contact simulation,the calculation method of contact forces and stress,and other methods simulating toppling failure were introduced.Several examples were used to illustrate the manifold method in comparison with G-B method put forward by Goodman and Bray and centrifuge model tests.The safety factor by manifold method was obtained.For comparison,the safety factors of the whole model and every block were also given by Limit Equilibrium Theory.It was shown that the numerical manifold method could be used to correctly simulate slope toppling failure and to calculate the safety factor as well.