Abstract: This paper reviews the status and the rehabilitation history of defective dams in China, as well as the classification method based on structure safety for defective dams. The respective rehabilitation measures for defective dams are proposed considering features of different kinds of dam defects. It also summarizes conditions for dam degrading and decommissioning and analyzes reasons that restrict the progress in dam degrading and decommissioning. It is of guiding significance to the large scale on-going rehabilitation works for defective reservoir dams in China.