Objective To observe the relationship and clinical application value of plasma asymmetric dimethylarginine (ADMA) concentration and acute coronary syndrome (ACS) as well as its subgroups in patients. Methods All the patients were received coronary artery angiography. ACS group (n=102) was divided into unstable angina (UA) sub group (n=51), non-ST-segment elevation myocardial infarction (NSTEMI) subgroup (n=27) and ST-segment elevation myocardial infarction (STEMI) sub group (n=24) according to clinical data, angiographic figure and electrocardiogram examination. The normal coronary patients provided as control group (n=24). The plasma ADMA was measured by enzyme linked immunosorbent assay (ELISA). Results The concentration of plasma ADMA in ACS group was higher than in control group (P<0.05). In sub-group analysis, the concentration of plasma ADMA in AMI group was higher than in control group (P<0.05). The concentration of plasma ADMA in UA group was higher than in control group (P<0.05). The concentration of plasma ADMA in NSTEMI group was higher than in control group (P<0.05). The concentration of plasma ADMA in STEMI group was higher than in control group (P<0.05), and no differences were found between UA group and AMI group. Area Under ROC Curve of positive group and negative group was 0.813（0.7