Objective To explore the effect and mechanism of sleeve gastrectomy （SG） for type 2 diabetes mellitus （T2DM） in Goto-Kakizaki （GK） rats. Methods Thirteen male GK rats at 12 weeks of age were randomly divided into SG group （n=7） and sham operation group （SO group， n=6）， receiving SG surgery and sham operation respectively.Body weight， food intake in 24hours， fasting plasma glucose， plasma glucagon-like peptide-1 （GLP-1）， and plasma Ghrelin of rats in 2 groups were measured or tested before operation， 1， 4， 10， and 26 weeks after operation. In 10 weeks after operation， fecal energy content of rats in 2 groups was tested， in addition， oral glucose tolerance test （OGTT） and insulin tolerance test （ITT） were performed to investigate the glucose tolerance and insulin sensitivity. Results ①Body weight：there were no significant difference on body weight between the 2 groups （P＞0.05）. Compared with time point of before operation， the body weight of both 2 groups decreased in 1 week after operation （P＜0.01）， but increased in 10 weeks and 26 weeks （P＜0.01）. ②Food intake in 24 hours：compared with SO group， the food intake of SG group were lower in 4 weeks and 10 weeks after operation （P＜0.05）. Compared with time point of before operation， the food intake of SG group were lower in 1， 4， and 10 weeks after operation （P＜0.05）， but lower only in 1 week in SO group （P＜0.05）. ③Value of fasting glucose：compared with SO group， the value of fasting glucose in SG group were lower after operation （P＜0.01）. Compared with time point of before operation， the value of fasting glucose of SG group were lower after operation （P＜0.01）， but decreased in 1 week only in SO group （P＜0.01）. ④Level of serum GLP-1：compared with SO group， the levels of serum GLP-1 in SG group were higher in 4， 10， and 26 weeks after operation （P＜0.05）. Compared with time point of before operation， the levels of serum GLP-1 in SG group were higher in 4， 10， and 26 weeks after operation （P＜0.05）， but levels of serum GLP-1 in SO group didn’t change significantly （P＞0.05）. ⑤Level of serum Ghrelin：compared with SO group， the levels of serum Ghrelin in SG group were lower at alltime points after operation （P＜0.01）. Compared with time point of before operation， the levels of serum Ghrelin in SGgroup were lower at all time points after operation （P＜0.001）， but levels of serum Ghrelin in SO group didn’t change significantly （P＞0.05）. ⑥Areas under curves （AUC）：the AUC of OGTT and ITT test in SG group were both lower than those of SO group （P＜0.01）. Conclusion SG surgery can induce the level of fasting plasma glucose， and canimprove glucose tolerance and insulin sensitivity with significant changes of levels of plasma GLP-1 and Ghrelin， sugg-esting that SG surgery may be a potential strategy to treat patient with T2DM but without obesity or insulin resistance.