Objective:To explore the hypoglycemic effect of gastrointestinal bypass and effects on glucagon like peptide -1(GLP-1)and insulin-like growth factor -1(IGF-1)levels in diabetic rats. Methods:A total of 60 SD rats were randomly divided into the control group,the sham operation group,the duodenal bypass group,and the jejunal bypass group. The diabetic model was established by injecting of 1% streptozotocin(STZ)intraperitoneally in the sham operation group,the duodenal bypass group and the jejunal bypass group. The surgical operations were performed accordingly. The levels of blood sugar,insulin,serum GLP-1,and IGF-1 were examined before operation and 1,3 and 8 weeks after operation. Results:The survival rates of rats were 100.00% in both the control group and the sham-operated group,and were 93.33% and 86.67% in the duodenal bypass group,and the jejunal bypass group,respectively. The blood glucose,GLP-1 and IGF-1 levels of the sham operation group,the duodenal bypass group,and the jejunal bypass group before operation were significantly higher than those of the control group,and the insulin level was significantly lower than that of the control group(P < 0.05);3 or 8 week after surgery,the body weight,and blood glucose of the duodenal bypass group and the jejunal bypass group were lower than those of the sham operation group at the same time point,and the levels of insulin,GLP-1,and IGF-1 were higher than those of the sham operation group at the same time point(P < 0.05);meanwhile,the body weight,blood glucose of the jejunal bypass group were lower than those of the duodenal bypass group,and the levels of insulin,GLP-1,and IGF-1 were higher than those of the duodenal bypass group(P < 0.05). Conclusion:Gastrointestinal bypass can be effective in the treatment of diabetic rats,and the effect increased with the increase of the length of small intestine. One of the mechanisms may be that gastrointestinal bypass increases the synthesis and secretion of GLP-1 and IGF-1.