This paper represents an effective approach in shape and material optimization of a vertical floating breakwater. Using the potential-flow theory, the hydrodynamic pressure deduced from sea wave's propagation has been computed based on the non linear theory of Stocks. Then, an analytical structural study of the floating breakwater, exposed to the wave pressure, is elaborated based on the frame theory. Finally, the optimization process is performed on the shape and type of material of a floating breakwater; where the structural deflections and the stress distribution constitute the constraints of the optimization problem.