Objective,2,To explore the clinical experience of TCM experts in treating ankylosing spondylitis.,Methods,2,8 TCM rheumatology experts or their academic successor， including ZHANG Ming-he， YAN Xiao-ping， FENG Xing-hua， TANG Xiao-po， ZHU Wan-hua， WANG Bei， LOU Yu-qian and WANG Yi-jun， were included to conduct semi-structured interviews， record and sort out the interview contents， and adopt ground ed theory to encode and analyze the interview data.,Results,2,Through the interview on eight subjects， 20 open codes were excavated. After further deepening the logical relationship， three main shaft codes of diagnosis and treatment of ankylosing spondylitis were obtained， namely， key points of syndrome differentiation， treatment principles and prescription and medication， and the theoretical framework of "clinical experience of famous and old Chinese medicine practitioners in treating ankylosing spondylitis" was initially constructed.,Conclusion,2,When treating ankylosing spondylitis clinically， famous and old Chinese medicine experts take tonifying kidney and dredging Du meridian， strengthening body resistance and eliminating pathogenic factors， comprehensive methods， treating by stages， applying classics， combining disease differentiation with syndrome differentiation and cooperating with modern test results as the treatment principles. Insect drugs， meridian-guiding drugs， drugs for balancing yin and yang， drugs for protecting stomach qi， drugs for combining diseases and products with feelings of flesh and blood are mostly used in the prescriptions.