The damped vibrations of non-homogeneous isotropic elastic infinite plate resting on elastic foundation are studied. The thickness variation is considered parabolically and non-homogeneity variation is taken as exponentially. In this paper a generalized eigenvalue problem is obtained by applying Frobenious method and suitable boundary conditions from which the values of a frequency parameter, deflection function and the corresponding mode shapes of vibration, for specific values of other parameters, are obtained.