The purpose of this study is to develop the method for designing sportswear that takes into account the solar irradiation. We calculated the net solar irradiance level by using the solar irradiation vector, the irradiance level and the normal vector of surface of the human CG model, and visualized the contour on the human CG model. On the basis of this data, we made a prototype of the sportswear that highly light-blocking fabric and highly breathable fabric are allocated on the appropriate region. This prototype is suitable under hot environment.