Abstract： Objective： To observe the clinical effect of Huoxue Zhuanggu tang combined with quadriceps functional exercising for knee osteoarthritis. Methods：A total of 120 cases of patients with knee osteoarthritis were selected and divided into the observation group and the control group according to the random number table method， with 60 cases in each group. Both groups were treated with diacerein capsules； the control group was additionally treated with quadriceps functional exercising， and the observation group was additionally treated with Huoxue Zhuanggu tang based on the treatment of the control group. Both groups were treated for six weeks. Before and after treatment， the scores of Visual Analogue Scale(VAS)， Western Ontario and Mcmaster Universities Osteoarthritis Index(WOMAC) and Lequesne Index， and the levels of superoxide dismutase(SOD)， malondialdehyde(MDA)， interleukin- 6 (IL- 6) and nitric oxide(NO) in serum in the two groups were compared. Results： After treatment， the scores of VAS， WOMAC and Lequesne Index in the two groups were decreased when compared with those before treatment(P＜0.05)，and the scores of VAS，WOMAC and Lequesne Index in the observation group were lower than those in the control group(P＜0.05). After treatment，the SOD levels in serum in the two groups were increased when compared with those before treatment(P＜0.05)， and the SOD level in serum in the observation group was higher than that in the control group(P＜0.05)； the levels of MDA， IL- 6 and NO in serum in the two groups were decreased when compared with those before treatment (P＜0.05)，and the levels of MDA，IL-6 and NO in serum in the observation group were lower than those in the control group(P＜0.05). Conclusion： Huoxue Zhuanggu tang combined with quadriceps functional exercising for knee osteoarthritis can effectively relieve pain and improve knee joint function， whose mechanism may be related to the decrease of levels of MDA，IL- 6 and NO in serum and the increase of SOD levels in serum.