Abstract: The spontaneous rupture of vulnerable atherosclerotic plaques and subsequent thrombus formation and myocardial necrosis are currently recognized as the primary mechanisms of acute coronary events. The dangerous of acute coronary events is mainly determined by plaque′s components, not by degree of luminal obstruction. Vulnerable plaque is characterized by a thin fibrous cap, accumulation of inflammatory cells, apoptosis, intraplaque hemorrhage, and revascularization. Several radionuclide probes target including apoptosis, macrophages, oxidized low density lipoprotein, matrix metalloproteinase, tissue factor, αvβ3 integrin and microcalcification have shown the potential to detect the rupture-proneatherosclerotic plaque in vivo.