[Purpose] The study aimed to analyze efficacy evaluation for early AS sacroiliac arthritis using MRI functional imaging [Methods]Forty-eight patients with early active AS who were examined respectively by MRI and clinical therapeutic indexes(BASDAI score,CRP,ESR) before medication and after comprehensive treatment of Chinese and Western Medicine. SPARCC scores were obtained by STIR sequence, and the values of ADCslow, ADCfast, f were obtained by IVIM sequence before and after treatment .Comparison of the changes and correlation between MRI evaluation indexes and clinical indexes before and after treatment.[Results]The clinical evaluation indexes (BASDAI score, ESR, CRP) and MRI evaluation indexes (SPARCC score, ADCslow, f) after treatment were significantly lower than those before treatment (p＜0.05). There were high correlation between SPARCC scores, ADCslow and BASDAI scores(p＜0.05).[Conclusion] Quantitative parameters of MR Functional Imaging (SPARCC scores and the values of ADCslow, f )can effectively evaluate the therapeutic effect of AS sacroiliac arthritis.