The main goal of this paper is to determine the stacking angles of composite plates in order to achieve the maximum fundamental natural frequency. In this regard, the equations of motion have been expressed using the Classic Laminat Plate Theory (CLPT), and the free vibration analysis of the plate has been done by applying different boundary conditions. In order to numerically analyze the behavior of free vibrations, the well-known generalized quadrature differential method has been used. This method estimates the partial derivatives of the function at a point by a linear series consisting of the weighted values of the same function at all points of the domain. Then, using this method, discretization of governing equations of the plate has been done. The discretized equations governing the plate have been solved using the eigenvalue analysis method. Then, in order to achieve the maximum fundamental frequency, the Simulated Annealing (SA) method is used. According to the obtained results, the differential quadrature method is found to be a suitable numerical method that requires short computation time to obtain natural frequencies. So far, this method has not been combined with the simulated annealing algorithm for optimizing the free vibrations of composite laminated plates, according to previous research. The combination of the differential quadrature method and the simulated annealing algorithm provides an effective tool for optimizing composite plates with minimal time cost.