Aim To investigate the intervenient efficacy of simvastatin and aspirin as well as blood sugar controlling therapy for carotid arteriosclerosis in patients with type 2 Diabetes. Methods 158 patients with type 2 diabetes and carotid arteriosclerosis were randomized into two groups.80 cases in the treatment group,were treated with both simvastatin and aspirin as well as hypoglycemia drugs;while 78 cases in the control group were treated with hypoglycemia drugs alone.Intima-media thickness(IMT) and internal diameter of Carotid arterial,the IMT and internal diameter ratio,carotid plaques score,glucose levels and the levels of serum lipids and were measured before and once a year after treatment for 3 years. Results Mean IMT of carotid artery and carotid plaques score were 1.02±0.11 mm and 3.8±2.4 respectively in the treatment group 1 year after treatment,showed no difference from that before treatment.But they were 0.89±0.15 mm and 2.7±1.6,0.89±0.14 mm and 2.5±1.1 after 2 and 3 years respectively,which were reduced significantly compared with that before treatment.The IMT and internal diameter ratio was also reduced significantly after treatment.Overall incidence of cardio-and cerebro-vascular events in the treatment group were 3.75% and 10.00% during the 3 years follow-up period,which were significantly lowed compared to the control group. Conclusions Long-term simvastatin and aspirin theraty could effectively delay and reverse the progression of carotid arteriosclerosis in patients with type 2 diabetes and prevent cardio-and cerebro-vascular events when combined with hypoglycemia drugs.