To evaluate the curative effect and safety of Bushen Qiangji Decoction ( BQD ) and Qingre Qiangji Decoction ( QQD ) in treating ankylosing spondylitis ( AS ) patients , and to verify the clinical utility of AS syndrome differentiation and treatment scheme [ Shen-deficiency induced stasis obstruction syndrome ( SDISOS ) and dampness-heat obstruction syndrome ( DHOS ) being two basic syndrome types , Shen invigorating blood activating method ( SIBAM ) and heat clearing dampness resolving method ( HCDRM ) being two basic treatment methods ] .