Abstract: Objective To study the radioprotective effect of catechines against radiation injury in mice.Methods Catechines were administered in mice intragastrically at the daily dose of 200 mg/kg for 10 consecutive days before whole body irradiation with 6 Gy X-rays.The body weight changes,survival time,30-day survival rate,and counts of peripheral white blood cells were recorded.Results The mice with catechine pre-treatment before X-ray exposure suffered less body weight loss than those without the treatment before exposure.Catechines markedly increased the survival time of the irradiated mice,and raised the 30-d survival rate of the irradiated mice to 53.33% as compared with the rate of 13.33% in the radiated mice without catechine pre-treatment.Catechines significantly promoted recovery of peripheral white blood cells.Conclusion Catechines have definite radioprotective effect against radiation injury in mice.