Abstract: Based on double Fourier series,the nonliear bending is analysed for is otropic rectangular plates with two adjacent edges simply supported and two other adjacent edges clamped under constant laterally distributed loads.Using orthogonality relations of Fourier series,we reduce governing nonlinear partial differential equations to an infinite set of system of nonlinear algebraic equations containing Fourier cofficients.Numerical results of central deflection bending stress and membrane stress are obtained by iterative computing method.