Spondyloarthritis（SpA） patients attending Nanfang Hospital of Southern Medical University will generate a large number of clinical condition scales, laboratory indicators, imaging data such as X-rays or MRIs in the course of multiple standardized follow-up visits, as well as medical specimens from some of the patients who undergo surgical treatments. The Department of Orthopaedic Surgery of Nanfang Hospital is looking forward to the future and proposes to establish a specialized cohort named "Nanfang SpA Bidirectional Specialized Disease Cohort" by simply recording the clinical and imaging data of the above patients who have attended the clinic, been treated routinely, and have been followed up in the department without any interventional research measures. The cohort is proposed to: (1) archive the disease characteristics, biochemical index data, and disease assessment scales of all SpA patients attending the Southern Hospital; (2) record the X-ray and magnetic resonance imaging data of the patients to establish the "Southern SpA Imaging Dataset". This provides strong support for subsequent SpA research projects and lays the foundation for subsequent large-scale transect studies and retrospective studies.