Abstract: Objective：To explore the clinical application and effect of prospective ECC-gated dual-source computed tomography coronary angiography (CTCA) with low tube voltage of 100 kV and low-iodine-concentration contrast agent to reduce radiation dosage. Methods：Totally 32 patients with coronary heart disease received dual-source CTCA. Prospective ECC-gated technique with the tube voltage of 100 kV and 300 mgI/mL iodine contrast agent was used. CT value of main segments of coronary arteries was measured. The scores of image quality and radiation dosage were assessed and analyzed. Results：CT value of every studied segment of coronary arteries was over 300 HU. The score of image quality was five in 289 segments, four in 148 segments, as well as three in 34 segments. The mean CT dose index volume (CTDIvol) and effective dose (DE) were 10.48±1.90 and (1.64±0.26) mGy. Conclusions：Prospective ECG-gated dual-source CCTA with low tube voltage of 100 kV and lowiodineconcentration contrast agent can reduce the radiation dosage without reducing image quality.