Ultrafast ultrasound imaging has been demonstrated to be an effective method to evaluate carotid stiffness through carotid pulse-wave velocity (PWV) with high reproducibility, but a lack of reference values has precluded its widespread use in clinical practice. The aims of this study were to establish reference values of PWV for ultrafast ultrasound imaging in a prospective, multicenter, population-based cohort study and to investigate the main determinants of carotid PWV. A total of 1,544 healthy Han Chinese volunteers (581 men [38%]; age range, 18-95years) were enrolled from 32 collaborating laboratories in China. The participants were categorized by age, blood pressure (BP), and body mass index (BMI). Basic clinical parameters and carotid PWV at the beginning of systole (BS) and at end-systole (ES) were measured using ultrafast ultrasound imaging techniques. PWV at both BS and ES was significantly higher in the left carotid artery than in the right carotid artery. PWV at BS was significantly higher in men than in women; however, no significant difference was noted in PWV at ES between men and women. Multiple linear regression analyses revealed that age, BP, and BMI were independently correlated with PWV at both BS and ES. PWV at BS and ES progressively increased with increases in age, BP, and BMI. Furthermore, age- and sex-specific reference values of carotid PWV for ultrafast ultrasound imaging were established. Reference values of carotid PWV for ultrafast ultrasound imaging, stratified by sex and age, were determined for the first time. Age, BP, and BMI were the dominant determinants of carotid PWV for ultrafast ultrasound imaging, which should be considered in clinical practice for assessing arterial stiffness.