OBJECTIVES: To measure the quality of life (QOL) in ankylosing sporidylitis (AS) patients treated with Infliximab in China. METHODS: Patients’ self-reported data were collected from a longitudinal survey which was conducted between June 10, 2009 and October 18, 2011 in AS patients at 40 urban hospitals in 23 cities in China. QOL was measured by Short Form-12 (SF-12) and each follow-up visit up to 8 visits. RESULTS: Of the 609 survey respondents, 13.0% were treated with Infliximab (experienced-Infliximab group (EIG)) at baseline and follow ups, while 87.0% were not treated with Infliximab at baseline but went on Infliximab treatment at the follow ups (new-Infliximab group (NIG)) . These two groups had no significant difference with respect to age, gender and duration. Comparing with those in the NIG at baseline, patients in the EIG reported higher mean scores of physical component (PCS) (42.7 vs. 35.8) and mental component (MCS) (47.5 vs. 43.0), as well as physical functioning (48.4 vs. 42.6), role physical (39.0 vs. 30.9), bodily pain (45.2 vs. 38.2), general health (36.9 vs. 31.4), vitality (52.5 vs. 47.6), social functioning (37.4 vs. 33.0), role emotional (45.8 vs. 38.7) and mental health (52.8 vs. 46.9). All differences between the two groups were statistically significant at P<0.05. After 14 weeks of Infliximab treatment, PCS and MCS had statistically significant improvements (10.7 and 9.8 respectively) from the baseline in the NIG, as well as all sub-domains of SF-12; in the EIG, there were significant improvements in PCS (8.1), general health (10.2) and mental health (4.1) from the baseline. CONCLUSIONS: The QOL was significantly better for patients who received Infliximab therapy than for those not treated with Infliximab. Infliximab initiating treatment and maintenance therapy both help improve patients QOL. The results indicate that Infliximab improves the quality of life of AS patients in China.