The magnetic charged system search (MCSS) is developed to optimum design grillage systems. The MCSS algorithm utilizes the governing laws for magnetic forces and includes magnetic forces in addition to electrical forces (defined by the standard algorithm). Also, a suitable constraint handling method to perform the optimal design is utilized. The displacement limitations as well as permissible stress constraints are employed as the constraints of the problem. The results of some numerical examples using the presented algorithm are compared to those of the standard CSS.