Objective To discuss the curative effect and safety of Bushen Qiangdu Fang in the treatment of ankylosing spondylitis （AS）. Methods The patients （n=50） were selected from outpatient sections and wards

and then they were treated with Bushen Qiangdu Fang one potion a day in the morning and evening for 6 months （one therapeutic course）. The changes of disease activity index

functional index

whole body pain scores

morning stiffness time

axial joint tenderness index

occiput to wall distance

finger to floor distance

activity of thorax

Schober sign

erythrocyte sedimentation rate （ESR） and C-reactive protein （CRP） were observed before and after the treatment. Results All indexes were significantly ameliorated （P<0.05 to P<0.001）. There were no changes observed in blood and urinary routine examinations and damage of liver and kidney functions. Conclusion Bushen Qiangdu Fang has a good curative effect on AS and is safe and reliable.