Objective:To assess the effects of Tai Chi (Chinese shadow boxing exercise) for improving the lower-limb muscle strength in elderly people.Methods:The PUBMED database (from 1950),EMBASE-ASP database (from 1974),Cochrane Library (from 1991),Elsevier sciences database (from 1990),OVID full text database (from 1997),Springer-link database (from 1997),The National Research Register database,ISI Web of knowledge (from 1963),Chinese Medical Citation Index/Chinese Medical Current Contents (CMCI/CMCC,from 1989),China Knowledge Resource Integrated Database (CNKI,from 1915),VIP database (from 1989),and Wanfang database (from 1977) have been searched only for the English and Chinese literatures updated to 10-30-2010.Two researchers independently assessed the methodological quality of studies,extracted and checked the data one another according to the include/exclude standards.Disagreement was resolved by discussions or with the third person.The Review Manage Software 5.0was used for Meta-analysis.Results:Eventually,2 randomized controled studies and 2 non-randomized controled studies met the inclusion criteria,with 163 subjects involved in the present meta-analysis.The meta-analysis demonstrated that Tai Chi exercise could improve the ankle flexor/extensor muscle strength and the knee extensor/flexor muscle strength,tested with an isokinetic dynamometer.The limb muscle strength increased significantly after Tai Chi exercise (P<0.01).Conclusion:The meta-analysis favours Tai Chi exercise for improving the lower-limb muscle strength in the older people.