Abstract　

Space-VLBI is a new observing system to reveal our universe with very high angular resolution. It is an extension of VLBI by adding radio astronomy satellite(s) to form very large aperture synthesis radio telescope. The world's first space-VLBI project was started as VSOP(VLBI Space-Observatory Programme) by the launch of Japanese space- VLBI satellite HALCA in 1987. It worked for several years with very wide international collaborations at 1.6, 5 and 22 GHz with the maximum baseline length of 30,000 km. The technology and some scientific results, mostly about AGN and jet phenomena, will be reviewed. The second space-VLBI mission now started is Russian RadioAstron project with the successful launch of the spacecraft in July 18, 2011. Second generation space-VLBI mission adding more sensitivity and mm-wave space-VLBI was planned and studied in detail as VSOP-2(Astro-G). Space-VLBI has potential future. Sub-mm space-VLBI will have the ultimate angular resolution in all electromagnetic spectrum, and must be realized to have fine detail of interesting astrophysical phenomena. Super massive blackholes and ambient phenomena are very interesting examples to be studied.