In order to overcome the problems on numerical simulation of structures with thin coating layers on its surfaces,a three dimensional analytical solution was presented for free and forced vibrations of simply supported rectangular thick plates with thick orthotropic coating layers on the top and bottom surfaces. In the absence of body forces, the elastic dynamic equations of the coated plate the constitutive description of the anisotropic coating layers, and the isotropic plate were given first.Then the suitable displacement functions that identically satisfy boundary conditions on the top and the bottom surface and the interface conditions between the plate and the coating layers were used to reduce equations to a set of coupled ordinary differential equations, which were then solved by the power series method. Finally by the comparison of the analytical natural frequencies, displacements and stresses of a rectangular coated plate applied a sinusoidal spatial pressure on its top surface with those given by the finite element method (FEM), the validity of the analytical solution given in this paper is testified
