Abstract: This paper presents a series solution to Von Kaman nonlinear equations of a rectangular plates supported be four beams under the action of lateral load.Using ordinary Fourier series for the edge displacement,double Fourier series for the deflection,and generalized Fourier se- ries for the stress function,governing equations are reduced to an infinite set of nonlinear algebraic equations,boundary conditions to an infinite set of linear algebraic equations for coefficients in these series.Numerical results for deflections of the plates,which are supported by four beams,are graphically presented.