Background: The plaque distribution and its relation to coronary distensibility in the entire single epicardial artery have not been studied. We assessed the hypothesis that the change of plaque burden from proximal to distal segment of the same coronary artery is related to the change of coronary distensibility. Methods: In 134 patients without overt coronary artery disease and medications (49.7짹8.9 yr, 75 men), IVUS assessment of left anterior descending artery (LAD) was obtained. Total 800 sites, consisting of each two site 0.5 to 1.0 cm apart in the proximal (n=134, 134), mid (n=134, 133) and distal segments (n=133, 132) respectively, were selected. The distensibility of the coronary artery (D) was defined as [(dA/A)/dP]x10³/mmHg, where A = the smallest luminal area in diastole, dA = difference between the largest and the smallest areas, dP = change in intracoronary pressure during a cardiac cycle. Results: As it was measured in the more distal LAD, there was a constant trend towards decreasing the plaque burden (p<0.001) in contrary to increasing the coronary distensibility (p<0.001) (Figure). There were no significant differences in the eccentricity among each site (p=NS, all). Conclusions: A progressive decline of plaque burden from proximal to distal segment of the angiographically normal LAD was related to a progressive increase of coronary distensibility. This finding suggests that the trial increasing the coronary distensibility may delay the development of atherosclerosis.