This paper presents the scenario on orbital experiment system using small satellites of the National Space Development Agency of JAPAN (NASDA). On this scenario, the main missions of the small satellites are the experiment of the earth observation, the satellite communications, and the others on orbit. And the small satellites will be launched by the small launch vehicle J-I of NASDA. As the first mission of this scenario, NASDA had studied the Optical Inter-orbit Communication Engineering Test Satellite (OICETS) system, and has started its development from the spring of 1993. Through this study, the small common satellite bus had been studied for the OICETS mission and other future missions. As the second mission, the Maneuvering, Rendezvous, and Docking Technology Experiment (MATEX) mission is studied now