OBJECTIVE To investigate the diagnosis of myocardial bridge and mural coronary artery (MB-MCA) with multi-slice computed tomography (MSCT) and clinical significance thereof. METHODS 900 patients suspected as with coronary artery disease (CHD) underwent 64-slice computed tomography performed by 3 radiologists independently. When consistency was obtained among the independent interpretations of the tomogram among them the diagnosis of MB-MCA could be confirmed. The length of MCA and thickness of MB were measured, and the situation of the nearby arteries were observed and recorded. Based on the above mentioned 3 items the reference scoring criteria were established. RESULTS 180 sites of MB-NCA were found in 167 (18.56%) of the 900 patients, 112 males and 55 females, aged 54.46 (33 - 84). 167 of the 180 sites of MB-MCA were located on the LAD (92.7%). MCA could be covered by MB in a form of semi-circularity (63.89%, 115/180) or circularity (36.11%, 65/180) The length of MCA was 18.7 mm +/- 10.2 mm, and the thickness of MB was 1.7 mm +/- 1.2 mm. 70% of the arteries proximal and/or distal to the MB-MCA were tortuous. Length of MCA < 10 mm, half-surrounding of MB, and smoothness of the proximal and distant vessels were scored as 1; length of MCA of 10 approximately 20 mm, thickness of MB < 1 mm, and tortuousness of the unilateral proximal or distant vessel were scored as 2; and length of MCA > 20 mm, thickness of MB > 1 mm, and tortuousness of the bilateral proximal and distant vessels were scored as 3. Coronary atherosclerosis was found in 88 of the 167 patients (52.69%). No significant correlation was found between coronary atherosclerosis and MB-MCA grade (u = 1.234, P > 0.05). CONCLUSIONS Sixty-four-slice CT can be used to confirm the presence of MB = MCA and the morphology of coronary artery with MB-MCA. Coronary atherosclerosis is not significantly correlated with MB-MCA grade.