Abstract: To study the significance of plasma thrombo modulin(TM) in coronary artery disease. Plasma TM was determined in 58 patients with coronary artery disease by an enzyme linked immunosorbent assay. The patients were divided intothree groups according to the results of coronary angiograms:group 1, single vessele disease; gorup 2: double vesseles disease;group 3, three and above vesseles disease. TM levels were significantly higher in group 1、2、3、than in control group(P<0.01), this levels of soluble TM form group3 were significantly increased compared with those from group 1(P< 0.05), and they indiabetes were significantly higher than in nondiabetes(P< 0.01). It suggests that the measurement of soluble TM in plasmais valuable inevaluating the degree and extent of endothelial in juries in patients with coronary artery disease.