Objective: To investigate the influences of enteral and parenteral nutrition suppled by gut on the gut microecology of the rats with abdominal infection. Methods: 14 Sprague-Dawley(SD)rats with abdominal infection models made with cecal ligation and perforation method were divided into two groups: parenteral nutrition (PN group, n=7) and PN+enteral nutrition (EN group, n=7) . The components of nutrition solutions in the two groups were isonitrogen and isocaloric. The rats were killed in the sixth day. The feces in cecum were cultured for anaerobic bacterial growth and analysed by bacterial group DNA fingerprint spectrum with random amplified polymorphic DNA . Results: ①The total death rate of the rats was 69.6%. Abdominal cavity abscess, liver abscess, and pulmonary infection commonly appeared in the model rats. ②The number of germs cultured in EN group was higher than in the PN group, but the quantity of Cl Perfrigens was higher , too. The gene stripe of probiotics group in EN group was similar to that in normal rats showed in the DNA fingerprint spectrum, but was significantly different in PN group with strange stripes. Conclusion: Application of early EN may correct the intestinal flora disturbance resulted from PN and increase the quantity of intestinal flora, but it can't control the species and may increase some conditional pathogenic bacteria .