PURPOSE: To determine the correlation between obstructive coronary artery disease and electron beamtomography coronary artery calcium(EBT CAC) scan and to measure the difference in calcium score according tosymptoms. MATERIALS AND METHODS: Fifty-six patients underwent EBT CAC scanning and either coronary angiography orstress thallium 201 scanning or the treadmill test. When the results were positive, coronary artery obstructivedisease(CAOD) was assumed to be present. The patients were divided into three groups : symptomatic CAOD,asymptomatic CAOD, and asymptomatic non- CAOD; those with a previous history of myocardial ischemia or who showedpositive results in any of the three tests relating to typical symptoms of angina were assigned to the symptomaticgroup. RESULTS: The number of cases assigned to group to group 1,2 and 3 was 19, 16 and 21, respectively; totalCAC scores were 571+/-751, 600+/-726 293+/-401, respectively. The difference in CAC score between asymptomatic CAODand asymptomatic non- CAOD was not statistically significant(p=0.079) but in asymptomatic CAOD, the score tendedto be higher. The CAC score was not different between symptomatic and asymptomatic CAOD(p>0.1). When the CACthreshold was 1, sensitivity was 89% and specificity was 14%;when the threshold was 200, sensitivity was 60% andspecificity was 67%. CONCLUSION: When the EBT CAC score is high, further evaluation provides early evidence ofcoronary artery obstructive disease.