Objective To study the protective effect of glutamine on the intestinal mucosal antioxidation in endotoxemic rats. Methods Twenty-eight male Wistar rats were randomly divided into three groups, group A:parenteral nutrition supplemented with glutamine, group B:TPN without glutamine,and group C:normal control. Endotoxemia was induced by continous intravenous infusion of lipopolysaccharide(LPS) at a dose of 2 mg/kg per day throughout the 5-day study period. The mucosal protein、DNA、ATP、SOD、MDA、GSH、sIgA were determined. Results The mucosal protein、DNA、ATP、SOD、GSH and sIgA content in endotoxic rats were markedly decreased, MDA was increased as compared with normal control(P＜0.05). The former indices in group A were improved and MDA content was decreased as compared with group B(P＜0.05). Conclusion Glutamine can improve gut energy metabolism, decrease the extent of mucosal injury of free radicals, and give an protective effect on the mucosal probably by increasing GSH.