Abstract: Objective To study the clinical outcome of arthroscopic debridement and synovium resection for hip lesion in patients with ankylosing spondylitis. Methods Arthroscopy,arthroscpic debridement and synovium resection were performed for hip lesion in 17 patients with ankylosing spondylitis from May 2003 to March 2007. Results All the patients were followed up for 14-59 months,averaging 36 months.The Harris and Oxford scores increased from 62.4±9.81 and 67.3±6.25 before operation to 85.5±11.4 and 87.5±10.4 after operation,respectively（P＜0.05）.The flexion and abduction function increased from 69.1o±10.3o and 10.2o±2.42o before operation to 88.6o±16.4o and 15.5o±3.45o after operation,respectively（P＜0.05）.The VAS scores decreased from 8.4±1.2 before operation to 5.9±1.6 after operation（P＜0.05）.Excellent,good,fair and poor outcome was achieved in 5,10,1 and 1 patients,respectively.Fifteen patients were satisfied with their outcome. Conclusion Arthroscopic debridement and synovium resection can effectively control the progression of hip lesion in patients with ankylosing spondylitis and relieve its symptoms.