Macrophage,an important component of the immune system,plays a crucial role in atherosclerosis and related cardiovascular diseases. Conventional wisdom holds that macrophages are derived from blood mononuclear phagocytic system and not renewable, but recent studies have shown that tissue macrophage can proliferate and has played a key role. Cell cycle regulators, bone growth factors and oxidized low density lipoprotein are closely related with macrophages in atherosclerosis. This article briefly reviews regulation of macrophage proliferation in atherosclerosis.