Legumain, also called asparaginyl endopeptidase, is one new member of the cysteine protease C13 family and plays various roles in human. In recent years, studies have displayed that Legumain is over expressed in a variety of tumors types and promotes the proliferation of tumor cells, tumor invasion and metastasis as well as angiogenesis through varied mechanisms. Further investigation of Legumain will be helpful to elucidate the pathogenesis and progression mechanism of malignant tumors and provide new molecular for targeted therapy of tumors.