Distributed small satellite synthetic aperture radar (DSS-SAR) is a new way to observe the earth's surface from space,which is proposed in the last years of the 20th century.In this paper,the DSS-SAR technique and its research progress are mainly discussed.After a brief review of its recent progress,the concept of DSS-SAR is described and its mission and means of implementation are presented.At last,the key problems and the prospect in this field are pointed out.