Purpose To compare the difference of CT coronary artery imaging quality under highflow oxygen uptake and normal breathing, and to investigate the effect of high flow oxygen uptake on the quality of CT coronary artery imaging.Materials and Methods 132 patients underwent coronary CTA examination using 256-slice CT (Philips), among them 71 patients were supplied with highflow oxygen, and the other 61 were asked to breathe normally. Coronary arteries were post-processed and reconstructed on AW 4.4 workstation. Scanning completion rate, signal to noise ratio (SNR), contrast to noise ratios(CNR) and image quality score ofcoronary segment using these two prospective ECG-gating techniques were compared.Results The scanning completion rate and image quality score of the highflow oxygen uptake group were significantly superior to those of the normal breathing group (P<0.05). However, there was no statistically significant difference of SNR and CNR between the two groups (P>0.05).Conclusion Imaging quality of coronary CTA can be improved using highflow oxygen uptake with reduced patient radiation dose, thus worth being used clinically as a simple and practicable method.