【Objective】To investigate the feasibility of low-dose contrast agent and special position design in 320- slice CT neck angiography.【Methods】Sixty patients with clinically suspected carotid or vertebral artery lesions were enrolled. They were randomly divided into two groups of G1 and G2，with 30 cases in each group. Body weight was measured and recorded before examination. 320 rows CT helix scan mode was used in both groups. Preventive intravenous access was given to the cubital vein of the right arm［1］ before the test. The contrast medium dosage was 0.6 mL/kg and the contrast agent injection rate was 4 mL/s. Group G1：used conventional position；Group G2：used auxiliary equipment to elevate the arm and angle outstretched position［2］. The other scanning and reconstruction parameters were the same as those in group G1. The CT values of each segment of the carotid artery and jugular vein were measured. The carotid artery （including the common carotid artery，internal and external carotid artery）and vertebral artery were observed and the degree of pulmonary vein damage，superior vena cava and right subclavian vein were observed. Comparing and analyzing objective image quality（vascular CT value）between the two groups.【Results】The CT values of right brachiocephalic vein，right subclavian vein and superior vena cava in in G1 and G2 groups were statistically significant（P<0.05）. There were no significant differences in the CT values of the left and right vertebral sinus between the two groups（G1 and G2）， the left and right internal carotid arteries（2 cm on the sinuses），and no significant difference（P>0.05）.【Conclusion】 During the neck CTA examination，Low dose contrast agent and special postural scanning can be used to meet the needs of clinical diagnosis. At the same time，the utilization efficiency of Contrast agent media is increased and the nephrotoxicity of Contrast agent media is reduced.