Objective: To investigate the protective effect of erythropoietin (EPO) on the acute renal injuries caused by abdomen open injury plus seawater immersion in rats.Methods: Sixty healthy male Wistar rats (clean grade) were evenly randomized into four groups,namely,EPO pre-treatment group,observation group,low-dose EPO treatment group and high-dose EPO treatment group.Acute renal injury was induced by abdomen open injury plus artificial seawater immersion (22℃).The serum creatine,BUN,creatine kinase,creatine kinase isoenzyme,TNF-α,IL-6,complement C3a,C-reactive protein,renal homogenate superoxide dismutase (SOD),and the renal pathological changes were observed and compared between different groups.Results: Acute renal injury was observed in all groups 3 hours after abdomen open injury plus seawater immersion,with increased serum creatine and BUN,but the rats survived after treatment.The serum creatine,BUN,creatine kinase,and creatine kinase isoenzyme in EPO pre-treatment group were significantly lower than those of the other 3 groups; the levels of TNF-α,IL-6,complement C3a,and C-reactive protein were also obviously decreased; the renal homogenate SOD was obviously increased; and the score of renal proximal tubule necrosis was obviously decreased.However,no significant differences were found between the high- and low-dose EPO groups concerning all the parameters (P>0.05).Conclusion: EPO pre-treatment has a protective effect on the acute renal injury induced by abdomen open injury plus seawater immersion in rats.