Abstract: Objective: A randomized and controlled study was conducted in patients with rheumatoid arthritis （RA） in order to assess the efficacy and safety of mobic.Methods: The patients were randomized to receive once-daily oral mobic 15 mg （n=24） or clinoril 200 mg twice daily （n=18） for 4 weeks. Results: After treatment, all the observed parameters were significantly improved in both groups （P ＜0.01 or P ＜0.05）, except the number of painful joints in both groups and grip strength in mobic group （P ＞0.05）. The rates of marked improvement were 29.2% and 33.3% in mobic and clinoril respectively. The rate of side effects in both groups was 16.7%. Conclusion: Mobic is well tolerated and effective in treatment of patient with RA. The efficancy and side effects are just the same in both groups.