Abstract: By using the modified iteration method of large deflection theory of plates with variable thichness[1], we solve the problem of circular plates with variable thickness subjected to combined loads under the boundary conditions of the clamped edges and get comparatively more accurate second-order approximate analytical solution.If the results of this paper are degraded into the special cases, the results coinciding with those of papers [1,2] can be obtained.In this paper, the characteristic curves are plotted and some comparisons are made.The results of this paper are satisfactory.