Abstract. The present paper provides mathematical model for the study of natural (free) vibration of non homogeneous tapered parallelogram plate on clamped boundary condition. Here non homogeneity (in material) of the plate's means that the density and Poisson's ratio varies circularly and exponentially respectively. For tapered, we assumed that thickness of the plate varies linearly in one direction. Bi parabolic temperature (parabolic in -direction and parabolic in -direction) variation on the plate is being viewed. Rayleigh Ritz method is used to solve the model (governing differential equation of motion).