Objective To investigate the value of ankylosing spondylitis(AS)disease activity score (ASDAS)and the Bath AS disease activity index(BASDAI)in evaluating disease activity in AS.Methods ASDAS and BASDAI were used to evaluate disease activity in patients with AS,taking the patients' global scores,physician global scores and treatment decision as the “gold standard” for disease activity.According to the “gold standard”,the patients were divided into low and high disease activity groups.Statistical analysis included descriptive statistics,linear correlation and regression and ROC curve.Results A total of 227 patients with AS were included.ASDAS and BASDAI showed good correlation with disease activity as reflected by the patients' global score[r for BASDAI,ASDAS based on ESR(ASDAS-ESR)and ASDAS based on C-reactive protein(ASDAS-CRP)were 0.713,0.698 and 0.725,respectively,P =0.000]and the physician global score(r for BASDAI,ASDAS-ESR and ASDAS-CRP were 0.771,0.782,0.847,respectively,P =0.000).Both scores showed good discriminative ability for high and low disease activity states.ASDAS-CRP had the highest sensitivity.Conclusion ASDAS is a promising tool for evaluating disease activity in AS patients.