In the range of infinitesimal deformations, the Lagrange's classical plate theory is widely used as a plate bending theory, but it is applied to thin plate only. Then, for thick plate improved theories in consideration of transverse shear are prepared. In the range of large deformations, in-plane deformation of plate is produced with large deflexion. Because magnitude of this deformation depends on plate thickness, we cannot explain the influence of plate thickness with transverse shear only. In this paper, we investigate the influence of plate thickness on large deformation of plate and the applicability of analytical result of the thin plate to thick plates on large deformation. Examples for analysis are uniformly loaded several thick circular plates is analyzed using finite-deformation theory. As a numerical method, the 3-dimensional finite element method which is formulated using the incremental theory based on the convected coordinates is used.