Objective To analyze the related factors associated with the effect of Roux-en-Y gastric bypass in Goto-Kakizaki rats.Methods In GK rats undergoing Roux-en-Y gastric bypass,the weight,food intake,and the fasting blood glucose were retrospectively analyzed before surgery and 1,3,6,12,24 weeks after surgery,and the glycosylated haemoglobin concentrations were retrospectively analyzed before surgery and 4,12,24 weeks after surgery.According to preoperative glycosylated haemoglobin concentrations,GK rats were divided into 3 groups(group A,HbAlc 6.5％-7.9％; group B,HbAlc 8.0％-9.9％ ; group C,HbAlc ＞ 10％).Results The fasting blood glucose and the glycosylated haemoglobin concentrations significantly decreased 1 week after surgery(P ＜ 0.01),on 24 weeks after operation,the fasting blood glucose levels decreased from(12.1 ± 3.0)mmol/L to(7.6 ± 1.3)mmol/L,and the glycosylated haemoglobin concentrations declined from(9.2％ ± 1.8％)to(6.3％ ± 0.8％).Preoperative fasting blood glucose was(11.1 ± 2.2)mmol/L and(15.8 ± 2.3)mmol/L respectively,and the preoperative glycosylated haemoglobin concentration was(8.6％ ± 1.4％)and(11.5％ ± 1.4％)respectively(P ＜ 0.01).Non-conditional Logistic regression analysis identified preoperative glycosylated haemoglobin concentrations as an independent predictor for the cure rate(P ＜ 0.01); Differences were significant between group A and group C,and group B and group C on the efficiency of the surgery(P ＜0.01).Conclusions Significant correlation established between glycosylated haemoglobin concentrations and the efficiency of the surgery,especially for those rats with preoperative HbAlc ＜ 10％.