On 1968 Dr. Peter Glaser introduced the concept of a large solar power satellite system in a high geosynchronous orbit for collection and conversion of solar energy into an electromagnetic microwave beam to transmit usable energy to rectennas on earth. With respect to it, U.S.A, Japan, E.U., etc. noted the Space Solar Power(SSP) as a future new energy resource, performed a substantial research and the concept design, and recently announced detailed plans for realizing SSP projects. While the new technology of SSP is developing, U.S.A. and Japan have a plan to provide the electric service by using SSP 2030. This paper presents the technology trend of advanced countries and the domestic strategies on the SSP development as a green energy and a new energy resource.