In order to investigate the effect of L-glutamine on gut immune function, 14 miniswines with 30% TBSA full thickness burns were randomly and equally divided into NON-GLN group and GLN group. GLN group animals were supplied with L-glutamine 0.64 g/day, and NON-GLN group received equal amount of non-glutamine amino acids. The S-IgA concentration of jejunal and IgA concentration of arterial blood were determined on PBD (post burn day) 1, 4, 7, 10. S-IgA concentration of ileal contents was measured on PBD10. The results showed that the concentrations of S-IgA in the jejunal and ileal contents as well as IgA in arterial blood decreased significantly after burns in NON-GLN group. L-glutamine supplement increased the excretion of S-IgA of intestinal mucosa in the GLN group. This result suggests that oral feeding of L-glutamine improves the intestinal S-IgA excretion after burns efficiently, and it plays an important role in the prevention of endotoxin and bacterial translocation after burns.