Heparanase (HPA) is a β-D-endoglycosidase of the only degradation of heparan sulfate proteoglycans in extracellular matrix in mammals.The related studies in recent years have suggested that HPA is closely associated with the formation and development of atherosclerotic plaques,and may be associated with the conversion from stable to unstable plaques.This article reviews the related studies of HPA in atherosclerosis progression,such as promoting plaque inflammatory response,synergy with proteolytic enzymes,and involving in hypercoagulable states,etc.