Background: The number of circulating endothelial progenitor cells (EPCs), insulin resitance (IR), and aortic stiffness are associated with a significant increase in the risk of coronary artery disease. Brachial-ankle pulse wave velocity (BaPWV) is an indirect maker of aortic stiffness and the serum Apo B/Apo-I ratio is an important marker of IR in non-diabetic, normoglycemic subjects. Quantity of coronary artery calcium is a noninvasive surrogate of coronary atherosclerotic burden that is strongly correlated with angiographic coronary artery disease and is predictive of future coronary heart disease events. We investigated the relation between circulation EPC counts and these markers. Methods: A total of 53 patients (60.2짹10.2 years, male 62.3%) with angiographically diagnosed coronary artery disease who had no history of diabetes were enrolled. Coronary atherosclerosis was assessed by measuring coronary calcification using multi-detector row computed tomography and expressed as a total calcium score. The number of EPC was measured in the peripheral blood before percutaneous coronary intervention. Results: The number of CD45lowCD34+VEGFR2+ cells was positively correlated Apo B/Apo A1 ratio (r=0.294, p=0.049), left BaPWV (r=0.464, p=0.010), and right BaPWV (r=0.445, p=0.014). CD45lowCD34+VEGFR2+ cell was not correlated total coronary calcium score. Linear regression analyses showed that the number of CD45lowCD34+VEGFR2+ cells was associated with Apo B/Apo A ratio and BaPWV (beta-regression coefficient 0.345, 0.312, 95% confidence interval 0.12-0.41, 0.04-0.15, respectively). Conclusion: The number of EPC was independently associated with IR and aortic stiffness.