Disease-Modifying Antirheumatic Drugs Cycle Combination Therapy Research

Inclusion Criteria: RA patients： * Male and female patients aged 18 - 75 years (inclusive). * Body weight between 50 and 100 kg (inclusive). * Post menopausal or surgically sterile female patients are allowed. Female patients of child-bearing potential may participate if they are already on a stable dose of methotrexate. Additional birth control details to be provided at screening. Male patients must use an effective contraception method during the study and at least for 2 months following the completion/discontinuation of the study. * Diagnosis of RA, classified by American Rheumatism Association 1987 revised criteria. * Active disease evaluation (DAS 28 \> 3.2). * Patients who using steroids before enrollment, the dose should not be more than 30mg/d, and remain unchanged for more than 30days. * Without use of other disease activity controlling drugs. * Get the informed consent. Exclusion Criteria: * Advanced patients with severe joints disability. * Pregnant or breast- feeding female patients. * Patients with severe primary disease or impairment of heart, brain, lung, liver (ALT or AST \> 1.5 normal value), kidney (sCr \> normal value), endocrine, and hematology system. * Concomitant with other rheumatic disease. * Alcohol taken or drug abusing patients. * Patients with congestive heart failure, QT prolongation syndrome or poorly controlled diabetes mellitus. Patients with a history of QTc prolongation will be excluded. * Patients who have received intra-articular or systemic corticosteroid injections having been required for treatment of acute RA flare (not being part of a regular therapeutic regimen) within 4 weeks prior to randomization.