ObjectiveThe aim of this study was to investigate the underlying cerebral hemodynamic mechanisms of 12 weeks of Tai Chi exercise to improve motor function in older adults by fNIRS technique.MethodsThirty-four healthy older adults were randomized into a Tai Chi group and a control group. The Tai Chi group received a 12-week Tai Chi intervention, and the control group did not receive any intervention. The subjects' motor functions were assessed before and after the experiment and hemodynamic indices of motor-related brain regions in the walking task state were collected.ResultsIn the within-group comparison before and after the intervention, the results of unipedal stability, Berg scale score and timed rise and walk test in the Tai Chi group were significantly improved compared with the pre-intervention (P<0.05); the oxygenated hemoglobin concentration in the primary motor cortex (M1) and the premotor area-assisted motor area (PMC-SMA) were all significantly increased compared with the pre-intervention (P<0.05). In the post-intervention inter-group comparison, the oxygenated hemoglobin concentrations in the M1 and PMC-SMA brain regions of the Tai Chi group were significantly higher than those of the control group (P<0.05).Conclusion12 weeks of Tai Chi exercise significantly improved the motor function and neural activation of motor-related brain regions in older adults.