This paper suggests a design methodology based on the use of Genetic Algorithm (GA) for optimizing a DC/AC converter scheme used for grid-connected photovoltaic system. The converter design is optimized to reach either maximum efficiency, or minimum size, or lowest cost. To achieve such requirements, Genetic Algorithm is used to search optimal design while a non-ideal averaged model is used to model the inverter. A simulation model is developed in MATLAB/Simulink environment for the overall system. The GA is implemented in MATLAB. All optimal results show the features of the modeling and optimization technique.