Objective To compare the effect of coronary enhancement at coronary CT angiography using contrast material injection protocol with dose adjusted to LBW with using protocols adjusted to total body weight. Methods A total of 200 consecutive patients undergoing DSCT CCTA without previous coronary stent placement, bypass surgery, congenital or valvular heart disease were included, and were randomly assigned to two groups. The contrast material dose of two groups were calculated by total body weight in TBW group and by measured lean body weight in LBW group. The injection durations of both groups were determined by using scan time plus 8 seconds divided total contrast material dose. Postcontrast attenuation measurements were obtained in AA above the coronary ostia, LM, LAD, LCX and RCA for each group. Mean absolute deviation were calculated in two group and analyzed. Results 1.The mean attenuations of AA, LM, LAD, LCX and RCA shows no significant differences between two groups. 2. The mean absolute deviation of aortic and coronary attenuation in TBW group was higher than the LBW group, and the result shows statistical significant. 3.Compare with nonobese patients, the aortic and coronary attenuations in obese patient were lower in TBW group. Conclusion By employing the lean body weight to calculate the contrast material dose needed for CCTA, it may lessen patient-to-patient enhancement variability while maintaining satisfactory aortic and coronary enhancement.