Based on anisotropic elasto-plastic finite element method developed by Owen,a nu-merical ana1ysis of composite laminate plates and shells with moderate thickness is undertak-en,The Huber-Mises yield surface extended by Hill and the nine-node Heterosis element areintroduced into the present model.In order to increase the computational accuracy and thespeed of convergence an improving arc-length iteration method for solving nonlinear incre-ment finite element equations is presented.Numerical examples are given and compared with available solutions.It is shown thatthe proposed method is more efficient than existing finite element methods.