OBJECTIVES: Ankylosing spondylitis (AS) is a chronic progressive autoimmune inflammatory condition that affects the spine and sacroiliac joints causing pain and stiffness in and around the spine. AS leads to irreversible structural changes and consequently impairs spinal mobility and quality of life (QoL). The aim of our study was to evaluate the impact of anti-TNF therapy (Infliximab) on clinical symptoms and QoL in AS patients in China. METHODS: A multi-center study was conducted from 2009 to 2011 in AS patients at 40 urban hospitals in 23 cities in China. Comparisons were made between patients who were treated with Infliximab at baseline and follow ups (experienced-Infliximab group, EIG) and those who were not treated with Infliximab at baseline but went on Infliximab treatment at the follow ups (new-Infliximab group, NIG). Clinical symptoms were measured by Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), and Bath Ankylosing Spondylitis Metrology Index (BASMI). Short Form-12 (SF-12) scoring system was used to calculate the physical and mental component summary scores (PCS, MCS). RESULTS: Total 644 AS patients were identified (mean age=29 years; 82.7% male). The average duration of AS was 3 years, with almost 24% patients suffering AS more than 5 years. At baseline, the mean scores reported from the patients in EIG were: BASDI 2.50,　BASFI 1.85, BASMI 1.71, MCS 48 and PCS 43, which were all significantly better than those in NIG. After 12 weeks Infliximab treatment, NIG patients improved significantly in BASDI (-2.97), BASFI (-2.11), BASMI (-1.79), MCS (-34.19) and PCS (-18.20) than baseline (all P<0.0001). CONCLUSIONS: AS patients using Infliximab have better quality of life and daily function activities than those not using Infliximab before. The findings of this study indicate a significant improvement in QoL of patients following initiation of Infliximab therapy in China.