Aim To study the role on oxidized low density lipoprotein (ox-LDL) in the process of aorta disease on type 2 diabetes mellitus rats. Methods Wister rats were divided into three groups radomly (normal controls,fed on high fat and high glucose diets,and diabetes group). In the insulin resistance (IR) stage, 10 th week and 20 th week after developed diabetes, the intima-media thickness (IMT) were detected using image analysing system, ox-LDL and GhbA1C were examined by ELAsA. Results In the 10th week 10th week and IMT in group C were significantly higher than in group A and B (p<0.05), there was not obviously different between group A and B, whereas IMT in group B were marked higher than in group A, this condition continue to the end of the experiments, meanwile we found the level of IMT was significantly correlated with ox-LDL (r=0.85,p<0.05) And ox-LDL was significantly correlated with HbA1C (r=0.87, p<0.05) by multiple regression analyse,whereas IMT was not significantly correlated with HbA1C. Conclusions ox-LDL has a significant role in the aorta disease of type 2 diabetes mellitus rats,It helps the development of macrovascular damage.