Abstract: Based upon the large deflection equation of anisotropic composite panels, an analytical method for the buckling under in-plane bending load of orthotropic composite laminates has been presented by utilizing Ritz method and the principle of minimum potential energy. Moreover, a stress analysis method for the buckling of composite laminates under bending-shear combination loads was presented as well. The result by the present method was compared with that by the finite element method (FEM). The result by both the present method and FEM agree very well. The expression for the present method is clear and concise, which is easy to be applied in engineering practices.