Abstract: The technical motivation that stimulated the initial research in adaptive structures was the goals of attenuating and controlling the vibration motion and maintaining the shape of large flexible space structures,which can be adapted through automatical response to internal or external stimulations by direct integration of actuators,sensors and controllers into the load-carrying structures.It is expected that adaptive structures will play an important and irreplaceable role in meeting the performance requirements of future large spacecrafts. An overview of the technology related to adaptive structures is presented in this paper. Included are the development background, definition and constitution, basic concept and theory, as well as critical technologies of adaptive structures.