Abstract: The extent of application of the classical laminated plate vibration theory and laminated plate vibration theory with consideration of shear deformation is examined by means of the accurate solutions for the free vibration of simply supported and arbitrarily cross-ply laminated rectangular plates.In the classical laminated plate vibration theory, the influence of the inertia forces in two directions in the plane of the plate is also studied. We came to the conclusion that this influence can be neglected.