Abstract： Objective： To observe the curative effect of Wenjing Juanbi tang combined with western medicine for rheumatoid arthritis(RA) with cold- dampness obstruction syndrome and its regulating effect on the levels of superoxide dismutase(SOD)， total antioxidant capacity(TAC) and malonaldehyde(MDA) in serum. Methods： A total of 120 cases of RA patients with cold- dampness obstruction syndrome were selected and divided into the observation group and the control group according to the random number table method，60 cases in each group. The control group was given methotrexate and low- dose prednisone acetate tablets，and the observation group was additionally given Wenjing Juanbi tang based on the treatment of the control group. Both groups were treated for three months. The clinical effect in the two groups was compared； the changes in the levels of erythrocyte sedimentation rate(ESR)， rheumatoid factor(RF)， C- reactive protein (CRP)， anti- cyclic citrullinated peptide(CCP)， and oxidative stress indexes including Superoxide dismutase(SOD)， total antioxidant capacity(TAC) and Malonaldehyde(MDA) as well as the symptom scores of cold-dampness obstruction syndrome before and after treatment in the two groups were observed. Results： After treatment， the total effective rate was 85.00% in the observation group，higher than that of 69.49% in the control group，the difference being significant(P＜ 0.05). The levels of ESR， RF， CRP and CCP in the two groups were decreased when compared with those before treatment(P＜0.01)，and the above four indexes in the observation group were lower than those in the control group(P＜0.01). The scores of cold pain in joints，cold limbs，morning stiffness，unfavorable flexion and extension of joints and fear of cold in the two groups were decreased when compared with those before treatment(P＜0.01)， and the scores of the above five items in the observation group were lower than those in the control group(P＜0.01). The levels of SOD and TAC in serum in the two groups were increased when compared with those before treatment，and MDA levels were decreased，differences being significant(P＜0.01)；the levels of SOD and TAC in serum in the observation group were higher than those in the control group，and the level of MDA was lower，differences being significant(P＜0.01). Conclusion：The therapy of Wenjing Juanbi tang combined with western medicine for RA of cold- dampness obstruction type can alleviate the clinical symptoms， improve the oxidative stress state，and enhance the clinical effect.