Major participants of energy-saving?reconstruction?in?existing?buildings sharing social responsibility is the inherent requirement of improving the comprehensive efficiency of energy-saving?reconstruction. This paper sums up the theoretical results on fulfilling the social responsibilities of domestic and foreign enterprises.; summarizes the practical experience that general foreign enterprises fulfill their social responsibilities; combs the progress and analyzes the problems of the domestic enterprises in the practice of fulfilling their social responsibility; analyzes the particularity of the existing building energy-saving market operation, project implementation and operation model, and puts forward the research direction of the social responsibility sharing mechanism of energy-saving reconstruction in existing buildings.