Abstract: In this study, free vibrations of laminated composite plates on elastic foundations are studied. The plates have three different conditions of elastic boundary. The boundary conditions of plates are free, simply supported and fully clamped. Plates consist of layers and layers are arranged at different angles. Plates supported by the springs of five different points. The natural frequencies of plates are calculated by the finite element method. Finite element method is developed to solve problem. In this method, equations of boundary conditions are written for the analysis. In Matlab programming, a special software developed for the solution of equations. Free vibration frequencies of the different boundary conditions are displayed graphically and the results of graphic are discussed.