Aim To investigate the relationship between plasma soluble thrombomodulin(sTM) with coronary artery disease(CAD) and explore its association with other risk factors of CAD in 74 male patients. Methods Plasma sTM was measured by enzyme linked immunosorbent assay(ELISA) in all subjects,including 50 patients with CAD and 24 controls.All the subjects were documented by coronary artery angiography.Clinical information,such as age,body mass index,homocysteine,etc,was analyzed. Results The plasma sTM in CAD patients(32.9±9.4 μg/L) was significantly higher than that in the controls(24.6±5.1 μg/L,P=0.0001).Univariate Logistic regression showed that sTM was a significant risk factor for CAD.Oneway analysis of variance showed the patients in different clinical severities had different sTM levels(P=0.000) and patients with acute myocaidial infarction(AMI) or unstable angina(UA) owned a higher sTM level than the patients with stable angina(SA) or controls.If all subjects were assigned to quartiles based on their sTM values and OR value was estimated by comparing the likelihood of different severities of CAD among the quartiles,the OR value of developing more serious CAD augmented 2.5-fold for each increasing quartile of sTM in an ordinal logistic regression.Likewise,and the OR value of developing one rank or more than one rank in Gensini' scores was 1.89 for each increasing quartile of sTM.Plasma sTM levels were only related to age,high sensitive C-reaction protein (hs-CRP) and D-dimer significantly among those variables.Furthermore,Gensini' scores correlated with sTM significantly(r=0.43,P=0.001). Conclusions As a maker for endothelial damage,the sTM level is closely related to the severity of CAD and the severity of diseased coronary arteries in male patients.