Bridge and ship hull structures are almost composed of the one way and the two way rib system. This paper introduces some methods of analysis of stiffened plates with all edges clamped, reinforced by angled stiffeners including the effects of transverse shear deformation. One of practical methods of analysis of a plate problem is the finite difference technique. According to the numerical results, it is concluded to consider the effects of transverse shear deformation for small ratio of plate length to thickness. The distribution of deflection and internal forces which is caused by the variation of stiffener angle are significant factors to be considered in the analysis of the stiffened plate. Theory and analysis of stiffened plate proposed in this paper should be used in design of them.