Now a days, the usage of composite materials is increasing widely in various sectors. Due to high strength to low density ratio, it will be strongly preferred. The aim of this study is to achieve the lightest composite panel structures using genetic algorithm optimization methods. This algorithm program aims to help fast tool design of the laminated composite panels using analytical formulas. Composite theories, structural optimization, genetic algorithm and panels theories are taken into account for the design. Structure was analyzed and optimized according to in-plane loading conditions for flat plates. The optimization algorithm was considered for simply supported, fixed and one-edge free boundary conditions. Plates strength were evaluated according to strain and Tsai-Wu failure theories. Contiguous plies constraint is added to extent scope of work. The final stacking of panel was analyzed in commercial FEM program to compare with analytical results.