Abstract: Radiation therapy occupies an irreplaceable position for cancer therapy. Most tumors are radiation resistant with hypoxic cells，so it's important to increase the radiosensitization. At present，the radiosensitization concept has developed including DNA damage，angiogenesis，cell signal transduction，cell cycle dysfunction, apoptosis，and other fields. This article reviews the recent literature and the relevant issues concerning the role of the mechanism，strategy，and drugs of radiosensitization.