The radiation injury models of mice were established and the preventive effects of superoxide dis-mutase (SOD) compared with amifostine from radiation damage were investigated. C57BL/6 mice were whole-body irradiated with 6 Gy X-rays and sacrificed by cervical dislocation at 24 h after irradiation. The red blood cells and white blood cells counts in peripheral blood, thymus index, spleen index, and hepatic antioxidant activity were determined, respectively. The results show that compared with the group received irradiation only, SOD pretreatment has significant effect on white blood cells counts meanwhile thymus index is significantly elevated by 19.1%. Amifostine pretreatment has also significant effect on white blood cells counts and spleen index is significantly elevated by 22.6%. In addition, SOD pretreatment can significant protect hepatic antioxidant activity and decrease nalondialdehyde (MDA) level by 12.7% in irradiated while the total anti-oxidizing capability (T-AOC) is up by 45.0%. However, amifostine treatment could only remarkably decreased MDA level by 22.3%.Cited