Abstract: Reperfusion therapy is one of the most important treatments for acute myocardial infarction (AMI). In some case, obstruction of vascular epicardium is relieved, whereas myocardial tissue hypoperfusion remains. This phenomenon is called “no-reflow” whose exact mechanism is still unclear. Many studies have shown that there are several possible mechanisms leading to the occurrence of no-reflow, among which are endothelial cell injury, neutrophil accumulation and release of oxygen free radicals. Prognosis of patients with no-reflow is often poor and there is no standard treatment for no-reflow. Drug therapy, thrombectomy, distal protection devices and ischemic preconditioning are the major therapeutic approaches. This review mainly describes the research progress of the no-reflow phenomenon.