Percutaneous coronary intervention （PCI） is one of the important means of treatment of coronary heart disease,early PCI treatment can restore a stable coronary blood flow,reduce infarct size,thereby improve prognosis and reduce case fatality rate. However PCI causes mechanical vascular injury,the Stent and Balloon dilatation causes endothelial denudation,intimal tear,activate the excessive proliferation of smooth muscle cells and platelet adhesion and aggregation,leading to stenosis and thrombosis. Drug-eluting stent Restenosis was reduced to a certain extent,but could cause to delay endothelialization and lead to late stent thrombosis formation. Bone marrow and peripheral blood endothelial progenitor cells （EPC） involvement of endothelial and angiogenesis,in atherosclerotic lesions may play an important role in the development process,this paper discusses the role,characteristics,mechanism and prediction mechanism and therapeutic aspects of EPC to the repair function of endothelial injury in patients with CHD after PCI.