An improved arc-length method based on the nonlinear finite element approach is applied to the postbuckling analysis of composite laminated cylindrical panels under axial compression. In the nonlinear finite element analysis, the updated Lagrangian formulation and the eight-node degenerated shell element are used. The composite cylindrical panels considered as numerical examples are unidirectional, cross-ply, angle-ply, and quasi-isotropic laminates. Experiments are conducted to verify the validity of the present analysis for a cross-ply laminate. Present finite element results show good agreement with experiments on buckling and postbuckling behaviour. There exist some differences between the initial buckling loads and the postbuckling load-carrying capacities of composite cylindrical panels.