Endothehal progenitor cells(EPCs) exist in peripheral blood and can differentiate into endothelial cells.Recent researches indicate that EPCs are involved in the neovascularization of several tumors and promote the growth and metastasis of these tumors.Meanwhile,EPC levels are correlated with the grade,stage,and overall survival of tumor patients.This article is focused on the roles of endothelial progenitor cells in tumor neovascularization.