Lymphotoxin-alpha (LTA) gene has been reported to have a genetic association with systemic lupus erythematosus (SLE), psoriasis, and rheumatoid arthritis. However, the association of LTA with ankylosing spondylitis (AS) has not reported. By case-control study, we carried out the high density limited genome scanning to the HLA class III region about 58 kb in Ningxia population (case 300 and control 385). In this study, 33 SNPs in LTA were genotyped in Ningxia population. We analyzed these SNPs and the haplotypes covering LTA. Only the distribution of TCC haplotype which contains mutation allele of LTA rs909253 was statistically significant(P=0.0005). The C allele frequency of the LTA rs909253 T/C polymorphism was higher in AS cases than that in the controls (28.5% versus 19.7%, P=2×10-4) in Ningxia population. The results suggest that there is a relevance between LTA and the susceptibility of AS, and we identified that the LTA polymorphism may be associated with AS in Ningxia population.