Abstract: According to the principle that the computed response and the measured response should be fitted,the parameter inverse problem of 2-D elastic wave equation is reduced to an optimal problem of nonlinear multimode functions.The evolution strategy algorithm is used to search the global optimal solution and the inverse results are compared with those using genetic algorithm.Numerical simulations show that inversion accuracy obtained using evolution strategy algorithm is much higher than that obtained using genetic algorithm.The evolution strategy algorithm is an excellent nonlinear inversion method.