Objective To compare the image quality and radiation dose between prospective ECG-trigering and retrospective ECG gating technique in coronary artery imaging. Methods 33 patients suspected coronary artery disease were included in this study and divided into experimental group (prospective ECG-triggering coronary artery imaging, heart rate < 65 bpm, 16 patients)and control group (retrospective ECG gating coronary artery imaging, heart rate < 75 bpm, 17 patients). Radiation dose was recorded for statistical analysis. At the same time, image quality was evaluated. Results There were no significant differences in image quality 3.2 msy. Effective dose reduced 76.47 %. Conclusions Prospective ECG gating coronary artery imaging can obtain the similar image quality compared with prospective ECG gating coronary artery imaging but the effective dose reduced 76.47 %. Prospective ECG gating coronary artery imaging has clinical value to peoples who are able to not accept high radiation dose and with low heart rate.