Abstract: The author discussed the problem of the nonlinear forced flexural vibration of anisotropic composite unsymmetrically angle-ply laurinated plates ^[1].This paper is a follow-up of the above.In the paper, the author discusses the geometric nonlinear;forced flexural vibration of anisotropic composite symmetrically laminated plates under the harmonic force,makes an analysis of the complete solution analysis process including computing examples, obtains the illustrative amplitude-frequency relationships of the laminated plates with different ply-direction angles and under the load of different magnitudes and analyzes the effect of the ply-direction angle of the symmetrically laminated plates on the amplitude-frequency relationships of nonlinear forced vibration.The solution analysis result thus obtained is reliable.here is no doubt that the paper develops the study of the nonlinear forced vibration of composite laminated plates and is a useful attempt for further study of other composites nonli-near dynamics.