Objective To established a rat model for type II diabetes and to investigate the gradual changes of myocardial fibrosis and myocardial AGEs/ RAGE levels in type II diabetes. Methods Male SD rats were fed high?fat fodder for 6 weeks, and then injected a small dose of streptozotocin (STZ, 30 mg/ kg) after overnight fasting for 12 h. The random blood GLU was detected on the 3th and 7th days, respectively, after STZ injection. The rats with random blood GLU concentration higher or equal to 16. 7 mmol/ L detected twice were considered as successful rat model of type II diabetes. Six rats of group C and six rats of group D fasting for 12 h were killed after intraperitoneal anesthesia at the 4th, 8th and 12th weeks after the successful establishment of type II diabetes models. Blood samples were taken for FBG and insulin detection. A portion of the left ventricle tissue was used for Masson staining and immunohistochemical detection of RAGE, and the other portion of the left ventricle was used for the detection of content of AGEs and Hyp. Results The FBG levels of group D were significantly higher, and the body weights of group D were significantly lower than group C at the same weeks. Blood insulin of the group D at the 12th week was significantly higher than that of the group C at the 12th week and group D at the 4th week. Myocardial Hyp, CVF, AGEs and RAGE of group D were significantly higher than those of the group C at the 8th, 12th weeks. The AGEs/ RAGE level of myocardium in the diabetic rats was positively correlated with CVF. Conclusions The model of type II diabetes is successfully established through intraperitoneal injecting a low?dose streptozotocin to SD rats which had been fed high?fat fodder. The rat models of type II diabetes demonstrate myocardial fibrosis at the 12th week after the successful establishment of diabetes. With the further development of diabetes, the myocardial fibrosis, content of myocardial AGEs, RAGE protein expression of the diabetic rats show an upward trend. The level of AGEs/ RAGE is positively correlated with the degree of myocardial fibrosis of type II diabetic rats.