 This study will enroll 100 cases of refractory rheumatoid arthritis RA patients in Chinese,who are in moderate or severe disease activity and insufficiency response or intolerance to DMARDs. The participants plan to be treated with Tacrolimus alone, or along with methotrexate MTX if participants were tolerant to MTX. The efficacy and safety of 6 month Tacrolimus treatment in RA patients will be evaluated with DAS28 and other disease activity indices. 