Abstract: Objective: To explore the factors influencing the peak time of head and neck CTA. Methods: The basic factors (gender, age, height, weight, heart rate, systolic blood pressure, diastolic blood pressure) and contrast medium injection parameters (flow rate, total amount of injection) during Test-Bolus injection were prospectively and randomly collected from 120 subjects with head and neck CTA. The peak time of head and neck CTA was obtained by Test-Bolus injection method at the cervical 4/5 level. The related factors influencing the peak time were analyzed using multiple regression mathematical method. Results: The peak time of female subjects (13.88±2.03)s was faster than that of male subjects (15.87±2.35)s, there was significant difference between genders. The peak time varied remarkably with factors such as age, height, and heart rate, which showed a certain linear relationship, with slopes of 0.043, 0.101 and -0.086 respectively, indicating that they were the main factors influencing the peak time of head and neck CTA. There was also significant difference between body weight and peak time, yet it turned out not the main factor through multiple regression analysis. There was no significant difference in systolic blood pressure, diastolic blood pressure and peak time. Although the contrast medium parameters of test-Bolus injection had certain effect on peak time, the difference was not significant. Conclusion: Gender, age, height and heart rate were the main factors influencing the peak time of head and neck CTA, and there was certain linear relationship with the peak time. The specific relationship provides a theoretical basis for optimizing the clinical scanning program for head and neck CTA.