Aim To explore the risk factors of atherosclerosis disease in the patients with type 2 diabetes mellitus. Methods Serum free fatty acid (FFA), total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDLC), high density lipoprotein cholesterol (HDLC), fasting blood glucose (FBG), glycosylated hemoglobin (HbA_1c), high sensitive C-reactive protein (Hs-CRP), tumor necrosis factor-α (TNF-α), fibrinogen (FIB) were tested in 170 type 2 diabetics and 74 non-diabetics as control group. These exposing factors and the incidence of atherosclerosis disease were compared in diabetic group and non-diabetic group by case control study. These exposing factors were compared in diabetics with atherosclerosis disease and without atherosclerosis disease and the risk factors of atherosclerosis disease were analyzed in statistic method. Results The incidence of atherosclerosis disease in type 2 diabetics was higher than that in control group (χ2=15.526, P=0.000, OR=3.088) and the confidence interval of 95% OR was 1.757～5.427. Multivariant Logistic regression analysis showed that the most important risk factor for atherosclerosis disease in type 2 diabetics was LDLC. The incidence of atherosclerosis disease in diabetics whose LDLC was higher than 2.6 mmol/L was 3 times that of whose LDLC was lower than 2.6 mmol/L (χ2=11.987, P=0.001, OR=3.073), and the confidence interval of 95% OR was 1.612～5.860. Conclusion The incidence of atherosclerosis disease in type 2 diabetics was 3 times that in non-diabetics. LDLC was the most important risk factor of atherosclerosis in type 2 diabetics.