Abstract：Objective：To observe the curative effect of sinew acupuncture combined with extracorporeal shock wave for knee osteoarthritis(KOA) in early and middle stage， and its effect on the expression of interleukin 1β(IL- 1β) and tumor necrosis factor α(TNF- α) in synovial fluid. Methods：A total of 80 patients with KOA in early and middle stage were divided into the observation group and the control group according to the random number table method，40 cases in each group. The control group was given the oral administration of imrecoxib combined with extracorporeal shock wave，and the observation group was given sinew acupuncture combined with extracorporeal shock wave. The clinical effect was compared between the two groups. Before and after treatment， the changes in the score of Western Ontario and McMaster Universities Osteoarthritis Index(WOMAC) and the contents of IL- 1β and TNF- α in synovial fluid were compared between the two groups. Results： The total effective rate was 95.00% in the observation group， and 77.50% in the control group， the difference being significant(P＜0.05). Before treatment，when compared the scores of pain，stiffness，and function of join in WOMAC between the two groups， there was no significance in the difference(P＞0.05). After treatment， the scores of pain，stiffness，and function of join in WOMAC in the two groups were lower than those before treatment，and the three scores above in the observation group were lower than those in the control group， differences being significant(P＜0.05). Before treatment，when compared the contents of IL-1β and TNF-α in synovial fluid between the two groups，there was no significance in the difference(P＞0.05). After treatment，the contents of IL-1β and TNF-α in synovial fluid in the two groups were decreased when compared with those before treatment(P＜0.05)，and the two contents above in the observation group were lower than those in the control group(P＜0.05). The incidence of adverse reactions was 7.50% in the observation group， lower than that of 25.0% in the control group，the difference being significant(P＜0.05). Conclusion：The therapy of sinew acupuncture combined with extracorporeal shock wave has a good clinical effect in the treatment of KOA in early and middle stage，which can improve joint function and reduce the levels of inflammatory factors in synovial fluid，with high safety.