Objective To explore the correlation between TCM syndrome differentiation types of knee osteoarthritis (KOA) and its MRI changes,so as to provide evidence for clinical diagnosis and treatment. Methods According to the standards of diagnosis and treatment based on overall analysis of symptoms and signs of TCM,72 patients with KOA were divided into 3 types:type of stagnation of tendons and muscles (22 cases),type of dampness infusion into bone and joints (23 cases) and type of inter-obstruction of phlegm and stasis (27 cases).All patients were performed MRI examination, in order to find out the correlation between syndrome differ classification of KOA and its MRI changes. Results 72 cases occurred with articular cartilage and meniscus injury.The incidence of synovial thickening of type of dampness infusion into bone and joints was the highest among the three types (P<0.01).The incidence of bone hyperplasia of type of inter-obstruction of phlegm and stasis was the highest among the three types (P<0.01).The incidence of joint free body formation of type of inter-obstruction of phlegm and stasis was the highest among the three types (P<0.05). Conclusion There is certain correlation between TCM syndrome differentiation types of KOA and its MRI changes.MRI could be used as a reference for different types of TCM syndromes.