Objective    To  detect the pathological expressions of  TNF-α  and  VEGF in interspinous ligament of patients with ankylosing spondylitis(AS)  in active stage.      Methods    The expressions of  TNF-α  mRNA and VEGF  mRNA in the interspinous ligament of patient with AS group and control group were detected by hybridization in situ.  Their different  results were compared by image analysis system and the correlation between TNF-α  mRNA

VEGF  mRNA  and both AS disease active index (DAI) and C reactive protein (CRP) was analysed respectively.     Results    The expressions of  TNF-α  mRNA and  VEGF  mRNA in the interspinous ligament of patients with active AS were positive

but those of the control group were negtive.  Statistical differences existed in the positive cell numbers and in image gray scale value of AS group (P0.01).  Significant correlation was observed between the expression of VEGF

TNF-α  and  CRP

BASDAI （P0.05）.     Conclusion    VEGF are the important factors in the pathological process in  patients with active AS. TNF-α

a core regualting factor

also plays an significant role in the pathogenesis of  AS.