OBJECTIVE: This study aimed to systematically evaluate the effect of Tai Chi on the balance function, mobility function, and gait function (including gait endurance, gait amplitude, and gait speed) of the lower limbs in patients with Parkinson's disease. METHODS: The "PICOS" principle was used to search seven English and six Chinese databases. Search for relevant studies published up to September 11, 2023, from the date of database creation. Two authors independently screened all eligible studies. The included studies were assessed for risk of bias based on the criteria outlined in Cochrane Handbook 5.1.0. Quantitative statistics and meta-analyses were conducted using Review Manager 5.4 software. RESULTS: Th 18 studies that met the inclusion criteria, 16 of which were included in the meta-analysis, included a sample of 963 cases from four countries. The meta-analysis revealed that Tai Chi was effective compared with conventional medication in improving balance function (MD = 2.06, 95% CI [1.35, 2.78], P <
0.00001, I CONCLUSION: Tai chi is a safe and effective rehabilitation intervention that can enhance the balance and mobility functions of the lower limbs in patients with Parkinson's disease.