Purpose: To investigate the coronary artery motion during cardiac cycle and the difference between the basal segment and mid segment of the coronary artery for cross sectional imaging. Methods: Consecutive eight patients suspected coronary artery disease were included in this study. The anteroposterial projection image and true lateral images were acquired simultaneously for more than 10 seconds with breath hold to eliminate the respiratory movement with biplane cine angiography at the frame rate of 30 f/s. The acquired cine images are separated to serial still images. Total 8 landmarks from branching points, 4 at basal segment and 4 at mid to apical segment were pointed as coordinates scene by scene. The two sets of coordinates are obtained for each landmark. The scale alignments are corrected by comparing distribution of the value of Z-axis coordinates and finally 3 dimensional coordinates are obtained. The velocity of each point is calculated by vector analysis. The motion velocity of the landmarks are analyzed in the aspect of left coronary artery (LCA) and right coronary artery (RCA), and the basal segment and mid to apical segment of the coronary artery. Result: The 3 dimensional location and velocity can be achieved and demonstrated on the space coordinates system. The coronary artery shows different pathway during systolic phase and diastolic phase. The duration of the velocity of less than 1mm/33ms is defined as rest period. The rest period is observed in the LCA at 30-42% and 63-78% of the cardiac cycle and in the RCA at 29-39% and 61%-75%. The mean rest period of LCA is 142 ms in systolic phase and 210 ms in diastolic phase. The mean rest period of RCA is 112 ms in systolic phase and 172 ms in diastolic phase. The mid to apical segment shows 99 ms longer rest period compared with the basal segment of the same individua���. Conclusion: The coronary artery shows different pathway during systolic phase and diastolic phase. There are rest periods of coronary artery motion at the 30-41% and 62- 77% of cardiac cycle. The coronary artery shows slightly different pattern of motion between basal segment and mid to apical segment.