OBJECTIVE To determine the morphological characteristics of myocardial bridge and mural coronary artery (MB-MCA) and initially quantify the changes of MB-MCA in diastole and systole phase with multiple-phase reconstruction technique using 256-slice CT angiography (256-slice CTA). METHODS We retrospectively collected the coronary artery imaging data of 861 patients undergoing 256-slice CTA with suspected or documented coronary artery disease. The images were reviewed by two independent radiologists, the diagnosis of MB-MCA was confirmed when consistency was obtained. The length, diameter and thickness of MB-MCA in the middle segment of LAD (LAD2) in diastole and systole phase were recorded, and changes of MB-MCA were calculated. RESULTS Among the 861 patients, 150 MB-MCA were found in 131 patients (15.2%). 99 MB-MCA (66.0%) were located in LAD2, the remaining 51 (34.0%) in the other segments of coronary arteries. The average length and thickness of MB was (17.6 ± 5.7) mm and (2.6 ± 0.7) mm, respectively. The average diameter change of MCA in LAD2 from systole phase to diastole phase was (1.2 ± 0.5) mm, and 41% of MCA have diameter stenosis more than 50% in systole phase. CONCLUSIONS The changes of MB-MCA from diastole to systole phase could be determined to some extent by 256-slice CTA multiple-phase reconstruction technique.