Abstract: Integrins are a group of significant cell adhesion molecules and participate in the regulation of critical functions through cellular signal trusduction, including cell adhesion, migration, proliferation, differentiation, and so on. The integrin-mediated signaling, meanwhile, may activate a variety of protein kinases after ionizing radiation, and then form different intracellular signal pathways in order to regulate the expression of gene. As consequence, these signal pathways induce the reduction of the radiosensitivity of tumor cells for survival event. To understand integrin-mediated signal trasduciton, therefore, has the vital influence on the study of radiosensitizer and radiotherapy.