[en] It has been well known that high dose or high-dose-rate of ionizing radiation could impair DNA repair and induce cancer or genetical disorders. However, the effect of low-dose radiation is not well identified, and a number of studies are currently under way using in-vitro and in-vivo systems. this study was designed to explore whether low-dose-rate (LDR) (0.07 cGy/hr) total body irradiation could be suppress the development of thymic lymphoma in AKR/J mice. In addition, radio-sensitive genes among high- and low-dose-rate radiation exposed mice were analysis using methodology of whole genome microarray. The data from this study demonstrates that a strong reduction effect of LDR irradiation (0.07 cGy/hr) in thymic lymphoma incidence contributed to elongate life-span. The commonly expressed apoptosis (Cd5l, Fcgr3, and pycard) and immune (pycard, Lilrb3, Igh-6, Fcgr2b, and MGC60843) related genes will be a potential radio-sensitizer for ionizing radiation. F rom these experimental studies it is evident that LDR whole body irradiation could be used in the planning of cancer treatment, and other measures such could be added to further promote the efficacy of cancer radiotherapy.