The paper presents formulation of the problem of layered plates composed of two various isotropic materials. We assume that the first material M1 is characterized by the following parameters: Young’s modulus E1 and Poisson’s ratio 1, whereas the second one by E2 and 2, respectively. Let us consider two modelling cases for functionally graded material (FGM) plates. These cases are related to an appropriate distribution of the material within two-layer and three-layer systems. Our objective is to compare the stiffness of both the two-layer and there-layer plates with the FGM plate containing various proportions between the material components M1 and M2.