Abstract Background Tai Chi exercise has been reported to enhance physical and mental health in the older adults; however, the mechanism remains elusive. Trial design We recruited 289 older adults practicing Tai Chi for over 3 years, together with 277 age-matched older and 102 young adults as controls. 168 Tai Chi practitioners were successfully matched to 168 older controls aged 60–69 based on a propensity score for statistics. Methods Cerebrovascular function was evaluated by measuring the hemodynamics of the carotid artery. Spearman correlation was performed to validate the age-associated physiological parameters. Results Cerebrovascular function in older adults significantly degenerated compared with the young, and was substantially correlated with age. Compared with the older control group, Tai Chi practitioners showed significant improvements in CVHI (cerebral vascular hemodynamics indices) Score (P = 0.002), mean blood flow velocity (P = 0.014), maximal blood flow velocity (P = 0.04) and minimum blood flow velocity (P