BACKGROUND The progression of coronary artery calcification (CAC) is known to increase the risk of future cardiovascular events. However, there is little data about CAC progression in Korea. We studied the rate and determinants of progression of CAC in asymptomatic Korean population. METHODS We evaluated 1661 asymptomatic persons (mean age 53.9짹7.0 years, male 92.3%) without history of ischemic heart disease. They underwent multi-detector computed tomography consecutively for screening subclinical atherosclerosis 2 or more times within mean interval of 1.5 (range 0.5-4.1) years. CAC was scored by Agatston method. Conventional and biochemical risk factors were measured at baseline. RESULTS At baseline, 854(51.4%) subjects had CAC. The mean CAC score increased from 53.3 at baseline and 73.5 at follow-up. Progression of CAC was observed in 773(46.5%) subjects and the average individual change in CAC score was 16.4짹40.8 / year. Mean progression rate of CAC score increased according to baseline CAC score (Figure1). The rate of progression in CAC was related to age (p<0.001), baseline CAC score (p<0.001), diabetes (p<0.001), body mass index (BMI) (p=0.004), low-density lipoprotein (LDL) cholesterol (p=0.01) in multivariate analysis. CONCLUSIONS This data will be helpful to interpret the serial data of CAC score. Also, the determinants of CAC advance, diabetes, BMI, LDL cholesterol should be controlled to prevent progression of coronary atherosclerosis in the field of primary prevention.