Objective To observe the effect of Roux-en-Y gastric bypass (RYGB) treatment and hepatic branch of the vagus on hypoglycemic outcome and glucagon-like peptide-1(GLP-1) in rats with type 2 diabetes, and the interaction of between the two. Methods Totally 45 type 2 diabetic rats were divided into four groups: sham operation (S group, n=10), sham operation with hepatic branch of the vagus resected (SV group, n=11), RYGB group (n=12), and RYGB with hepatic branch of the vagus resected (RYGBV group, n=12). The body mass, fasting blood-glucose (FBG), fasting serum insulin (FINS) and concentrations of fasting serum GLP-1 were examined before and after surgery. Effects of RYGB and the hepatic branch of the vagus on GLP-1 levels were analyzed. Results Compared with S group and RYGBV group, RYGB group had significantly decreased body mass(P<0.05) and significantly improved levels of serum GLP-1 and insulin (P<0.05); FBG level in RYGB group was significantly lower than that in S group (P<0.05) and similar to that in RYGBV group. The effect of RYGB on fasting serum GLP-1 was stronger than that of liver branch of the vagus nerve, and there was interaction between the two (P<0.05). Conclusion RYGB treatment has satisfactory treatment effect for type 2 diabetes, and care should be taken during RYGB surgery to preserve the hepatic branch of the vagus.