Objective To investigate the effects of HLA-B27 in disease activity and the clinical features of axial spondyloarthritis(SpA). Methods Clinical data of 112 patients with axial SpA was collected and studied prospectively. Clinical manifestations and laboratory examination results of 82 HLA-B27 positive and 30 HLA-B27 negative patients with axial SpA were analyzed. Data source was from Chinese Rheumatism Data Center. Results (1)The average age of onset of HLA-B27 negative patients was significantly later than that of the positive patients , and there was no significant difference in the course of disease and the proportion of male and female patients. (2)The ratio of severe lesion of hip ,peripheral arthritis ,attachment inflammation and systemic symptoms of HLA-B27 negative group were significantly lower than those of HLA-B27 positive group. Familial aggregation phenomenon,uveitis and spine radiology changes in two groups had no significant difference.(3)The changes of disease activity index including erythrocyte sedimentation rate and C-reactive protein increased in HLA-B 27 negative group was significantly lower than those in HLA-B27 positive group. Conclusion There is strong correlation between axial SpA and HLA-B27. The average age of onset of HLA-B27 negative patients was significantly later than that of the positive patients. HLA-B27 negative patients manifested severe symptoms and worse prognosis.