Abstract: AIM: To evaluate the application of dual-source CT 100 kv tube voltage in low-dose computer tomography coronary angiography. METHODS: Seventy patients suspected of or diagnosed as having coronary disease( with BMI 20-24% and sinus rhythm) were randomly divided into two equal groups:study group( 100 kv tube voltage) and control group( 120 kv tube voltage). The image quality and radiation dose of the two groups were compared. RESULTS: No statistical difference was found in the scores of imaging quality between the two groups. The average effective radiation dose of the study group and control group were( 3. 29 ± 0. 56) m Sv and( 7. 22 ± 1. 43) m Sv,respectively,with significant differences between groups. CONCLUSION: Application of 100 kv tube voltage in CT coronary angiography can ensure good image quality and high diagnostic accuracy of coronary artery stenosis while it significantly reduces the radiation dose.