Objective To observe the change of regulatory T cells expression in severely burned rats gut ,To investigate the effects of regulatory T cells on CD3+CD4+ /CD3+CD8+lymphocytes and its relation with gut-origin endotoxin translocation .Meth-ods Fifty SD male rats were randomly divided into normal control group(n=10)and burn model groups(n=40) .Rats were burned to achieve Ⅲ degree scalding ,and a 30% total body surface area(TBSA) burn model was made .Rats were sacrificed before(normal control group) and after 0 .5 ,1 ,2 ,4 burn hour(PBH groups) .Flow cytometry techniques were used for the detection of the expres-sions of regulatory T cells and CD3+CD4+ /CD3+CD8+ lymphocyte in intestinal lymph nodes which were separated .The dynamic turbidity method was used for detection of endotoxin levels in portal vein blood .Results The expression of regulatory T cells was negativelycorrelatedwithCD3+CD4+ /CD3+CD8+ lymphocyteratio(r= -0.827,P<0.01)inintestinallymphnodeofrats,while the regulatory T cells was positively correlated with ET levels in portal vein blood plasma .(r=0 .782 ,P<0 .01) .Conclusion The expression of the regulatory T cells in intestinal lymph node in severely burned rats was increased compared to that in normal con-trol group .Regulatory T cells suppressed the expression of intestinal T lymphocytes ,leading to gut immune inhibition .The translo-cation of intestinal endotoxin has a close relationship with regulatory T cells in severely burned rats .Regulatory T cells could have portal effects on intestinal immunity barrier .