Aim To detect the contents of endogenous ADMA in coronary artery disease(CAD) patients and investigate the relationship between each other.Methods 37 patients with CAD(M=31,F=6,mean age=62.0±10.3) were selected at random for study,and 18 normal people(M=9,F=9,mean age=55.0±9.8) were selected as control.All of them received coronary angiography to determine whether he has CAD and the grading of pathological changes.Serum levels of ADMA,L-arginine and SDMA were measured by HPLC,and serum contents of lipid were detected by automatic biochemic analysis apparatus.Results The results showed that serum content of ADMA was significantly increased in CAD as compared to normal people(3.24 ±1.45 μmol/L vs 2.03±1.12 μmol/L,p< 0.01),while that of L-arginine and SDMA were similar in both groups(SDMA 1.98±2.19 μmol/L vs 1.27±1.44 μmol/L,p> 0.05;L-arginine 100.0±48.6 μmol/L vs 107.9±49.1 μmol/L,p> 0.05).ADMA showed a trend to elevate with severity of coronary artery disease and had significantly increased as comPared to normal people(p< 0.01).Serum level of ADMA only correlated with the severity of coronary artery disorder(r= 0.28,p< 0.05) but has no relation with the atherosclerosis risk factors such as lipid,age and BMI(p> 0.05).Conclusions ADMA significantly increased in CAD patients and the elevation of endogenous ADMA may be a risk factor of CAD.