Abstract: Objective:To investigate the best time of enteral nutrition(EN),and observe the effects of early enteral nutrition(EEN) on intestinal mucosa damage after burn injury.Methods:Rats were inflicted with 30% total body surface area full-thickness burn.Eighty-eight Wistar rats were randomly divided into the sham burn control group(C group),early enteral nutrition group(EEN group,in which enteral nutrition was given at the sixth hour after burn) and delayed enteral nutrition group(DEN group,in which enteral nutrition began at the 24th hour after burn).The intestinal mucosal potential difference(PD),intestinal mucosal blood flow(IMBF),jejunum pH(pHi),level of plasma lipopolysaccharide(LPS),diamine oxidase(DAO) activity and intestinal mucosa damage index in all rats were detected before burn and at postburn 0.5,1,3,7 and 10 days(PBD).Results:After burn injury,compared with C group,the levels of PD,IMBF and pHi in burned rats were markedly decreased(P<0.01),while the LPS content,DAO activity and mucosa damage index were significantly increased(P<0.05 to P<0.01).Compared with DEN group,the PD and IMBF at PBD 1 to 10 and pHi at PBD 1,PBD 3,PBD 10 in EEN group were significantly high(P<0.05 to P<0.01),but the LPS content at PBD 3 to 10 and DAO activity at PBD 3 were obviously low in EEN group(P<0.01).No apparent discomfort,such as vomit,abdominal distension and diarrhea in two groups were found.Conclusions:Early enteral nutrition can improve the intestinal mucosal blood flow,reduce the intestinal damage,and maintain the structure and function of intestinal mucosa after burn injury.