Aim To investigate the effects of atorvastatin on the level of endothelial microparticles （EMP） and carotid artery intima-media thickness （IMT） in type 2 diabetes mellitus （T2DM） patients. Methods To select 90 cases of type 2 diabetes mellitus resident patients,aged between 45 and 75 years old，who were randomly classified into the atorvastatin group and simvastatin group. Under the circumstance of the intervention of life style,all patients undertook oral antidiabetic drug and/or insulin therapy simultaneously,and with aspirin 0.1 g qd. Atorvastatin group was given atorvastatin 20 mg more every night,simvastatin group was given simvastatin 20 mg more every night. The entire course of treatment lasted 24 weeks. The level of EMP,low density lipoprotein cholester （LDLC）,IMT was detected before and after the treatment,and the correlation between them was analyzed statistically. Results In the atorvastatin group and simvastatin group,the IMT decreased significantly （P<0.05） after therapy,while the plasma concentration of EMP,LDLC were decreased （P<0.05）,and the ability of atorvastatin lowering IMT,EMP and LDLC was stronger than the effect of simvastatin. There was positive relationship existing in the values of EMP,LDLC and IMT between the two groups before and after the therapy（P<0.05）. Conclusion Statins was capable of reducing the IMT,LDLC and EMP in patients with T2DM. Its anti-atherogenic ability was not only associated with the lipid-lowering effect,but also might be related to the inhibition of EMP release. Atorvastatin was superior compared with simvastatin on reducing both LDLC and EMP,which might account for the phenomenon of the stronger atherosclerosis resistant of atorvastatin compared with simvastatin.