A rigid body-spring element method is used to evaluate the static and dynamic stability of slopes or dam foundations. The versatility of the method applies well to both static and dynamic problems for blocks of arbitrary polyhedral shape with various reentrant surface features. Examples show that the safetyfactor obtained in this wayagrees well with theoretical solutions. The dynamic safety factor determined with this method varies with time, which differentiate it from the results of the limit equilibrium method or the finite element method. The method also makes it possible to search for the most probable sliding mass.