Objective To observe the and influence on intestinal mucosa on type 2 diabetes rats and to research the function of glucagon-like peptide-1 (GLP-1).Methods Healthy male SD rats were randomly divided into normal operation group (NO),normal control group (NC),diabetic operation group (DO) and diabetic control group (DC).The GLP-1,plasma glucose and insulin were tested preoperatively and 1,2,4,8 weeks postoperatively.Intestinal mucosa were examined by hematoxylin and eosin (HE) stain 2 months after operation.The mucosal thickness and villus height were measured by histological analysis.Results The DO group' s and NO group' s GLP-1 increased from (7.38 ± 1.71) pmol/L and (7.23 ± 1.59) pmol/L to (17.80 ± 1.39) pmol/L and (15.48 ± 1.21) pmol/L (P ＜ 0.05) at 8th week after gastric bypass operation respectively.The GLP-1 level of DO group was higher than that of DC and NC groups at corresponding time (P ＜ 0.05).The DO group' s fasting plasma glucose level was decreased which from (17.71 ± 1.99) mmol/L (preoperatively) to (5.95 ± 0.51) mmol/L (8 weeks postoperative) (P ＜ 0.05).The plasma glucose of DC group was higher than DO group at corresponding time (P ＜0.05).The DO group' s fasting plasma insulin increased from the preoperative (11.93 ± 0.75) mmol/L to (14.80 ± 0.78) mmol/L (P ＜ 0.05)at 8th week after gastric bypass operation respectively.Postoperative pathologic exam showed that the mucosal thickness and villus height in DO group and NO group were significantly higher than DC group and NC group.Conclusion The glucagons-like peptide-1 plays an important role on hypoglycemic effect of diabetic type 2 rats treated by gastric bypass operation.