Objective: To investigate the common cause of spinal surgery in ankylosing spondylitis (AS) and to develop reasonable and effective treatment programs for rhematologists. Methods: In this study, 79 AS patients (72 males, 7 females) hospitalized in the Department of Orthopedic and received spinal surgery in Peking University Third Hospital from January 2007 to July 2013 were investigated retrospectively. The causes of the spinal surgery were analyzed. Results: The majority of the surgery were of cervical vertebra surgery for 59 cases (74.7%), followed by the thoracolumbar vertebra, thoracic vertebra, cervicothoracic vertebra, and lumbar vertebra. The common causes of AS spinal surgery were instability (53.2%) including fracture and dislocation caused by trauma mostly, followed by compression symptoms (34.1%). However, the orthopaedic surgery (12.7%) was not the predominant surgery causes. The most common cause of cervical surgery was cervical spondylosis (25 cases), followed by cervical fracture (22 cases) and cervical dislocation (10 cases). For cervical fracture, the most common site was C7 (8 cases). Atlanto-axial vertebral lesions (13 cases) induced by dislocation, subluxation, instability and fracture were common in cervical vertebra surgery. The age and disease duration of atlantoaxial surgical patient’s were less than other parts of the cervical surgery. Thoracolumbar vertebra surgery included thoracolumbar kyphosis orthopaedic surgery (10 cases), and fractures (6 cases), which mainly occurred in T11-12 vertebrae. According to the time of admission for surgery, the cases of AS that received spinal surgery were 34 from 2007 to 2008. The number of the cases that accepted the surgery decreased gradually year by year. Conclusion: The majority surgery section was cervical vertebra, and atlanto-axial vertebral lesions were not rare as we thought. The main etiology of spinal surgery for AS patients was instability, e.g. fracture and compression symptoms. Of course, trauma accounted for the relative percentage of this phetonomenon. Although, the annual number of patients who receives spinal surgery is decreasing, to go to make early diagnosis and treatment, and to standardize patient education for AS patients are still important.