Abstract：Objective：To observe the clinical effect of modified Fuzi tang combined with western medicine for ankylosing spondylitis(AS) with cold-dampness obstruction syndrome. Methods：A total of 80 cases of patients were randomly divided into the control group and the observation group， 40 cases in each group. Both groups were given meloxicam tablets and thalidomide tablets，and the observation group was additionally treated with oral administration of modified Fuzi tang. Both groups were treated for six months. Before treatment as well as after three-month and six-month treatments，the scores of Visual Analogue Scale(VAS) for evaluating spinal pain，the scores of Bath Ankylosing Spondylitis Functional Index(BASFI)，the scores of Bath Ankylosing Spondylitis Disease(BASDAI)，Physician's Global Assessment(PGA)，and the syndrome scores of kidney-governor vessel deficiency were evaluated；the levels of C-reactive protein(CRP) and erythrocyte sedimentation rate (ESR) were detected， and the standard- reaching rates of Assessment of SpondyIoArthritis International Society(ASAS)20， ASAS50 and BASDAI50 were compared between the two groups. Results：After treatment，the standard-reaching rate of ASAS20 was 97.5% in the observation group， higher than that of 77.5% in the control group(P＜0.01)； the standardreaching rate of ASAS50 was 82.5% in the observation group，higher than that of 57.5% in the control group(P＜0.05)；the standard-reaching rate of BASDAI50 was 70.0% in the observation group，higher than that of 47.5% in the control group(P＜ 0.05). After three- month treatment， the VAS scores of spinal pain， the syndrome scores of kidney- governor vessel deficiency，the scores of PGA，BASFI and BASDAI，and the levels of CRP and ESR in the two groups were decreased when compared with those before treatment(P＜0.01)；after six- month treatment，the above five scores and the levels of CRP and ESR in the two groups were decreased when compared with those after three-month treatment(P＜0.01). After threemonth and six- month treatments， the VAS scores of spinal pain， the syndrome scores of kidney- governor vessel deficiency，the scores of PGA，BASFI and BASDAI，and the levels of CRP and ESR in the observation group were all lower than those in the control group at the same period(P＜0.01). Conclusion： Based thalidomide tablets and onmeloxicam tablets， the therapy of modified Fuzi tang in treating AS patients of cold- dampness obstruction type can better control symptoms like spinal pain，inhibit the activities of the disease，and improve clinical effect.