Spaceborne SAR-GMTI Systems have the ability to detect, track and relocate moving targets of the ground or the sea. The systems may provide high quality information for battlefield command, pinpoint strike and state evaluation, which is an important technique for space based reconnaissance. In this paper, Spaceborne SAR-GMTI Systems and relevant research process are introduced. The significant researches and development status quo in this field are discussed, and their limitations and key techniques are analyzed. Finally, the technique challenge and research emphasis are proposed.