Prior quantitative analysis of coronary artery compensatory remodeling is limited by individual variation of arterial size and arterial tapering. Therefore, we developed a new analytical method resolving this limitation and analyzed coronary compensatory remodeling using perfusion-fixed coronary arteries of WHHL rabbits, an animal model for spontaneous coronary atheroscl erosis. In the new anal ysis, we evaluated how lumen area or arterial size was changed with accumulating atherosclerotic plaques compared to before plaque developed. The lumen area modestly decreased below 10% cross-sectional narrowing (CSN), remained constant from 10% to 68% CSN, and diminished sharply despite continued remodeling above 70% CSN. Up to 70% CSN, arterial remodeling progressed quantitatively to maintain constant arterial wall shear stress as well as lumen area. Quantitative anal ysis eliminating the previous limitation provides the novel insight that coronary compensatory remodeling in atherosclerosis maintains lumen size up to 70% CSN in proportion to wall shear stress.