Objective To investigate the feasibility of using low concentration contrast agent and low tube voltage combined iterative reconstruction in head and neck CT Angiography(CTA). Methods 100 patients underwent head and neck CTA were prospectively enrolled in this study. They were randomly divided into group A and group B. For patients of group A 100kVp tube voltage, low concentration contrast agent (Visipaque 270mgI/ml) and iterative reconstruction (iDose4) were used in CTA, while for patients of group B 120kVp tube voltage, usual-concentration contrast agent (iohexol 350mgI/ml) and filter back projection (FBP) reconstruction were employed in CTA. The mean CT value and noise of carotid artery, the background CT value, the dose length product (DLP) were recorded, and then calculated the signal-to-noise ratio (SNR), contrast to noise ratio (CNR), effective dose (ED) and iodine intake. Using 5 point scale the image quality was evaluated by two radiologists. Results The mean CT value, CNR, SNR value of group A were higher than that of group B, while ED and iodine intake of group A were lower than that of group B, the differences were statistically significant between two groups (P<0.05). The image quality score had no statistically difference between two groups (P>0.05). Conclusion Double low dose technique combined with iterative reconstruction in head and neck CTA can get high quality images, meanwhile significantly reduce the radiation dose and the intake of contrast agent iodine.