Objective To compare the efficacies of different duration moxibustion on the Du meridian for ankylosing spondylitis of kidney yang deficiency type.Method Eighty-seven patients with ankylosing spondylitis of kidney yang deficiency type were randomized to 60 min,75 min and 90 min moxibustion on the Du meridian groups,which received corresponding duration moxibustion on the Du meridian in addition to oral administration of enteric-coated sulfasalazine tablets.The spinal pain Visual Analogue Scale(VAS)score,the Patient Global Assessment(PGA)score,the Bath Ankylosing Spondylitis Function Index(BASF...