Abstract: The optimum design of composite laminated structures subjected to multiple constraints,such as stresses,displacements and frepuency,is described in this paper,Variables are ply thicknesses and angles of or thotropy,A new method,quasianalytic sequence quadratic program method(SQP),is applied.With this method,a computer program SOD is compiled.Computational results for several typical examples show that the SQP method performs satisfactorily,and a considerable weight reduction can be achieved in tho optimum design of composite laminated structures.