Abstract: Vulnerable plaque rupture is the leading cause of acute cardiovascular diseases. Macrophages are main inflammatory cells closely related to the rupture of vulnerable plaques. Early diagnosis of vulnerable plaque can reduce the mortality of acute cardiovascular diseases. With the development of molecular imaging, the possibility for early identification of vulnerable plaques may come true. This review summarizes the changes of molecular markers of macrophages in vulnerable plaques and the molecular probes that can target macrophages.