Both ankylosing spondylitis (AS) and Takayasu's arteritis (TA) are infrequent, and their association is even more rare. Our objective was to assess their association and characteristics in our patients. We conducted retrospective analysis of our hospital inpatients from June 2000 to July 2011 who had both AS and TA. We used modified New York criteria for ankylosing spondylitis (1984) as AS diagnosis criterion and American College of Rheumatology Classification Criteria for Takayasu's Arteritis as TA diagnosis criterion. All clinical data, lab data, and radiological data were collected. Six patients were included in our study because they fulfilled our AS and TA criteria, four males and 2 females, aged from 18 to 35 years old. Four patients were HLA-B27 positive and 2 were negative. All patients' inflammatory markers such as erythrocyte sedimentation rate and C-reactive protein were high. The clinical characteristics of patients with both diseases did not seem to be different from that of patients with AS or TA alone in China. All patients were first diagnosed as AS, then found TA 3-20 years later. After diagnosed those patients having AS and TA, patients were given prednisone and cyclophosphamide and their symptoms improved gradually. Our study provides further evidence of the association of TA with AS. We should know that some AS patients can do have TA. To AS patients who have fever, bruit, or pulselessness, we should suspect that they have TA.