Aim To investigate the relationship between serum levels of inflammatory factors,adiponectin and atherosclerosis in the patients with type 2 diabetic mellitus(T2DM). Methods 125 cases of T2DM patients were divided into two groups according to the carotid intima-media thickness(IMT) as follows: 65 cases of non-atherosclerotic diabetic patients and 60 cases of atherosclerotic diabetic patients.30 non-diabetic subjects were recruited as normal control.The clinical characteristics were collected for each patient.Serum fasting plasma glucose(FPG),glycation hemoglobin A1c(GHbA1c),fasting insulin(FINS) 2 hours postprandic plasma glucose(2hPG),lipid profiles levels were measured.Serum levels of adiponectin,intercellular adhesion molecule-1(ICAM-1),tumor necrosis factor-α(TNF-α) and high sensitive C-reactive protein(hs-CRP) were also detected.Insulin resistance index(HOMA-IR) was calculated. Results The serum levels of total cholesterol,triglyceride(TG),low density lipoprotein cholesterol(LDLC),FPG,2hPG and GHbA1c were significantly higher in the T2DM group than that of normal control group(P<0.05).And the serum levels of TG and LDLC were higher in atherosclerotic T2DM patients than that of non-atherosclerotic T2DM patients(P<0.05).The serum levels of TNF-α and hs-CRP and HOMA-IR in atherosclerotic patients were significantly higher than that of in non-atherosclerotic and normal control group(P<0.05).However,serum adiponectin level in arteriosclerotic group was lower than that of other two groups(P<0.05).There were negative correlation between adiponecin and IMT,ICAM-1,TNF-α,hs-CRP and HOMA-IR(r=-0.574,-0.635,-0.681,-0.768 and-0.752,P<0.01).There were positive correlation between HOMA-IR and ICAM-1,TNF-α and hs-CRP(r=0.657,0.706 and 0.688,P<0.01).TG,LDLC and HOMA-IR were risk factors of T2DM complicated with arteriosclerosis according to multiple regression analysis. Conclusion Inflammatory factors and adiponectin are involved in the pathogenesis of diabetic vascular complications.The protective effects of adiponectin may be performed through its anti-inflammation to improve insulin resistance and delay the development of atherosclerosis.