Abstract: OBJECTIVE To study the effect of Lycium barbarum on the oxidative damage of kidney in rats induced by X-ray radiation. METHODS Fifty ♂ SD rats were randomly divided into blank group, model group, low, medium and high dose group of Lycium barbarum(0.63, 1.26, 2.52 g·kg^-1), with average 10 rats in each group. Every 24 hours, the Lycium barbarum group was given a dose of Lycium barbarum decoction, blank group and model group were given the same amount of distilled water. After 5 d of continuous intragastric administration, the rats in each group beside the blank group were given X-ray irradiation at the waist and back, radiation dosage of 4 Gy. After radiation, the rats in the same way continued to be irrigated. The body weight, diet and mental state of rats in each group were measured before gastric administration, and the quality of life of rats in each group was evaluated. The rats in each group were sacrificed after 5 d of gastric administration, then detected the rat kidney spleen index and renal function, renal oxidative injury and the pathological injury and expression of renal oxidative damage response protein Nrf2 and apoptosis protein caspase3, caspase9. RESULTS Compared with the blank group, quality of life, kidney index, SOD and GPX of the rats in the model group were significantly decreased(P<0.05), the content of BUN, Scr and MDA, pathological damage score, Nrf2, caspase3 and caspase9 increased significantly(P<0.05). Compared with the model group, the quality of life, renal index, SOD and GPX in the low, middle and high dose groups of Lycium barbarum were increased in varying degrees. The content of BUN, Scr and MDA, the score of pathological damage, the expression of Nrf2, the expression of caspase3 and caspase9 were all decreased, among which the high dose group was the most obvious(P<0.05). CONCLUSION Lycium barbarum can reduce the renal damage induced by X-ray radiation in SD rats, and its mechanism may be achieved by improving the scavenging ability of the kidney tissue to free radicals, thereby alleviating the oxidative damage and cell apoptosis caused by X-ray on the kidney tissue.