The vehicle based on WIG (Win In Ground effect) is expected and investigated as one of the future high speed vessels on seaway. In this paper, the shape optimization problem of 2dimensional WIG is discussed as a fundamental study with respect to WIG. For this purpose, the panel method is used for the fluid flow analysis around WIG and the nonlinear programming is used as the optimization method. Numerical examples are shown for several optimization problems. Experimental verifications are also shown by using a devised test method of WIG for a small wind tunnel.