Abstract： Objective： To observe the effect of modified Guizhi Shaoyao Zhimu tang combined with thunder- fire moxibustion on bone metabolism and gait parameters in patients with knee osteoarthritis(KOA). Methods ： A total of 152 cases of KOA patients in accordance with the inclusive criteria were selected and divided into two groups according to different treatment methods， 76 cases in each group. The control group was treated with modified Guizhi Shaoyao Zhimu tang，and the combination group was additionally treated with thunder-fire moxibustion based on the treatment plan of the control group. Both groups were treated for eight weeks. Before treatment and after four and eight weeks of treatment respectively， the levels of bone metabolism including osteocalcin(BGP)， osteoprotegerin(OPG)， β- collagen degradation product(β- CTx) and receptor activator of NF- κB ligand(RANKL) as well as the gait parameters including peak torque(PT) of flexor and angle of peak torque(AOPT) were detected. Results： After four and eight weeks of treatment respectively， the levels of BGP，OPG，PT and AOPT in the two groups were higher than those before treatment，and the levels of β-CTx and RANKL as well as the scores of joint swelling and pain，unfavorable flexion and extension and activity limitation were lower， differences being significant(P＜0.05). When compared the above indexes after eight-week treatment with those after fourweek treatment respectively， there was significance in differences(P＜0.05). After four and eight weeks of treatment respectively，the levels of BGP，OPG，PT and AOPT in the combination group were higher than those in the control group， and the levels of β-CTx and RANKL as well as the scores of joint swelling and pain，unfavorable flexion and extension and activity limitation were lower，differences being significant(P＜0.05). After eight-week treatment，the total clinical effective rate in the combination group was higher than that in the control group， and the incidence of complications was lower， differences being significant(P＜0.05). Conclusion： The therapy of modified Guizhi Shaoyao Zhimu tang combined with thunder- fire moxibustion for KOA patients can improve gait parameters and bone metabolism， and alleviate their clinical symptoms.