The invention discloses a method and a reagent for prediction of ankylosing spondylitis susceptibility. According to the invention, genomic DNA of a host cell is extracted and the genotype of site + 879 in a second intron zone of the AIF1 gene of a subject is determined so as to predicate susceptibility of the subject to ankylosing spondylitis; if the genotype of the single nucleotide polymorphism site + 879 is CC, lowest ankylosing spondylitis susceptibility is obtained, and if the site + 879 contains a T allele, i.e., the genotype is CT or TT, highest susceptibility is obtained. The invention has the following advantages: correlation between the AIF1 gene polymorphism site and the ankylosing spondylitis is elaborated for the first time; the method for predicting ankylosing spondylitis susceptibility is provided; and the method is applicable to prevention, auxiliary diagnosis and treatment of ankylosing spondylitis and can also be used for research and development of a novel drug.