Abstract: Abstract Objective: To observe the correlation of lipoprotein(a)[Lp（a）] levels to the extent , severity of coronary artery lesion in coronary artery disease (CAD) patients with 2 type diabetes mellitus. Methods: A total of 163 CAD patients angiographically documented were divided into two groups including moderate stenosis group and severe stenosis group according to severity of coronary artery lesion, divided into three groups including monovessel disease group, bivessel disease group and multivessel disease group according to the extent of coronary artery lesion. 54 subjectswithout CAD as control group. Serum lipid levels （total cholesterol: TC; triglycerides:TG; high-density lipoprotein-cholesterol:HDL-C; low-density lipoprotein -cholesterol:LDL-C; Apolipoprotein A-I : ApoA-I; Apolipoprotein:ApoB） were measured. Results: The Lp（a）levels were significantly higher in moderate stenosis group and severe stenosis group as compared to the controls, and there was no difference between moderate stenosis group and severe stenosis group. The Lp （a） levels were significantly higher in monovessel disease group, bivessel disease group and multivessel disease group as compared to the controls, and higher in multivessel disease group as compared to monovessel disease group and bivessel disease group. No difference of TC, TG, HDL-C, LDL-C, ApoA-I, ApoB levels among moderate stenosis group , severe stenosis group and control group was found , and there was no difference among monovessel disease group, bivessel disease group, multivessel disease group and control group. Logistic regression analysis indicated that Lp（a）levels were independently associated with the extent, severity of coronary artery lesion in Type 2 diabetic patients with CAD. Conclusion: Our data suggest that Lp（a）levels may be helpful in determining the extent, severity of coronary artery lesion in Type 2 diabetic patients with CAD.

Key words: Lipoprotein（a）, Coronary artery disease, 2 type diabetes mellitus, Coronary artery angiography