To investigate the effect of motion correction by SnapShot freeze (SSF) in coronary CT angiography at different levels of enhancement. Sixty-four patients who underwent gemstone coronary CT angiography were divided into two groups by aortic enhancement on the original section of the left coronary artery: group A (n = 30) < 400 HU and group B (n = 34) >= 400 HU. The end-diastolic and end-systolic phases with the least motion were determined for each vessel from a retrospective ECG-gated scan, and reconstructed using a standard algorithm (STD) and SSF. The STD-derived image quality score was 3.5305 +/- 0.5971 in group A and 3.4665 +/- 0.6266 in group B, and the SSF-derived image quality score was 3.6244 +/- 0.5252 in group A and 3.6964 +/- 0.506 in group B. No significant difference was found in STD-derived image quality score between the groups (t = 1.510, P = 0.131), while a significant difference was noted in SSF-derived image quality score between the groups (t = -2.024, P = 0.043). SSF-derived image scores were higher than those from STD in both groups (P < 0.001). STD-derived image quality scores of LAD, LCX, and RCA were lower than those from SSF, and the differences were statistically significant (P < 0.001). SSF can effectively improve the motion artifacts of coronary CT images, especially for RCA, and higher aortic CT enhancement results in greater image quality improvement.