Proprotein convertase subtilisin/kexin 9(PCSK9) is a serine protease which can induce the degradation of low density lipoprotein receptor(LDLR), increase the level of low density lipoprotein cholesterol(LDLC) in plasma. PCSK9 participate in various mechanisms promoting atherosclerosis. Recently, a number of clinical trials have confirmed that PCSK9 inhibitors have potential anti-inflammatory, anti-platelet, atherosclerotic plaque stability and other effects. This article reviews the research progress of PCSK9 and PCSK9 inhibitors from the aspects of the structure and regulatory factors of PCSK9, and the treatment of atherosclerosis by PCSK9 inhibitors.