Objective:To explore the traditional Chinese medicine (TCM)syndrome types of ankylosing spondylitis(AS), and providethis article provided reference for the objective diagnosis of AS syndromes. MethodsInformations of 278 AS patients based on TCM four diagnostic methods were collected. Common factors were extracted and symptom loads were measured by factor analysis. Syndrome groups were summarized by systematic cluster analysis in order to determine the TCM syndrome types of AS.  Results:24 common factors were extracted from clinical diagnostic informations of AS patients by factor analysis, and the factor scores were used as variables to cluster them.The basic TCM syndromes of AS could be divided into four categories, including nephrasthenia cold syndrome, yin-deficiency of kidney combined with yang-deficiency and dampness-heat syndrome, moist heat arthralgia spasm combined with spleen-deficiency syndrome, and stagnation of blood stasis syndrome.  Conclusion:It was feasible that factor analysis combined with cluster analysis to induce AS syndromes, according to fundamental theories of TCM.