To raise the economics of Space Solar Power System (SSPS) that is to supply large energy from space to the ground and is expected for practical application in 20-30 years, weight reduction and improvement of the lifespan need to be sought to reduce transportation costs and life cycle costs. In relation to the SSPS research that has been conducted by JAXA, present report suggests a new vision for material development applying the Japan-developed FGMs concept and proposes some concepts of innovative materials in which the advantages of FGMs are fully utilized.