Knee osteoarthritis (OA), a leading issue nowadays, is becoming one of the most common degenerative joint disorders in the worldwide as the sharp increase of aging population. It remained unclear whether Tai Chi was effective for posture control improvements in aged populations with knee osteoarthritis. The aim of this study was to systematically evaluate the effects of Tai Chi on improving balance function and posture control in elderly patients with knee osteoarthritis by updating the latest trial evidence. METHODS: Web of Science, PubMed/Medline, Embase, Scopus, PEDro and Cochrane library were searched up to October 1st, 2020 to identify RCTs evaluating Tai Chi for improving balance function and posture control in older adults with knee osteoarthritis. The primary outcomes were 6-minute walk test (6 MWT) and time up and go test (TUG), The secondary outcome was 'Western Ontario and McMaster Universities Osteoarthritis Index' (WOMAC) Physical Function Score. This meta-analysis was performed with RevMan Version 5.3 software. RESULTS: A total of 603 participants with knee osteoarthritis in the 11 RCTs were included. The results of meta-analysis showed that: The Tai Chi group was associated with better performance in 6-minute walk test (6 MWT), time up and go test (TUG) and WOMAC Physical Function Score than the control group [(MD: 46.67, 95% CI 36.91 to 56.43,P<0.001)], [(MD: - 0.89, 95% CI -1.16 to -0.61, P<0.001)], [(MD: -11.28, 95% CI -13.33to -9.24, P<0.001)]. CONCLUSIONS: This meta-analysis provides evidence from 11 RCTs that Tai Chi could be an excellent physical training strategy for improving posture control ability in older adults with knee osteoarthritis. Assuming that Tai Chi is at least effective and safe in most areas, it could be used as an adjuvant and reliable training method for balance upgrading and postural control improvements for older patients with knee osteoarthritis. Supported by the National Social Science Fund of China (NO.16BTY065).