Objective To investigate the MRI typical imaging characteristics of Giant Cell Tumor of Tendon Sheath(GCTTS), and its diagnostic value on GCTTS. Methods A total of 43 cases with GCTTS confirmed by operation and pathology in our hospital from May 2015 to September 2017 were all given MRI scanning, imaging data and clinical data of patients were collected, imaging characteristics and detection condition of GCTTS in MRI examination were analyzed. Results All the 43 cases of GCTTS showed welldefined parosteal tendon soft tissue mass or soft tissue mass around the tendon. And 35 cases were localized type giant cell tumor, 8 cases were diffuse type giant cell tumor. 24 cases of lesions showed iso-intense signal on T1WI, 12 cases of lesions showed hypointense signal, 7 cases of lesions showed slight hypo-intense signal. 14 cases of lesions showed mixed signal on T2WI, 9 cases of lesions showed slightly hyperintense signal, 11 cases of lesions showed obviously hyperintense signal, 9 cases (20.00%) of lesions showed low signal. There were 9 cases given MR enhancement scan, with homogeneous or heterogeneous density, and enhancement region with clear border. Conclusion MRI can displayed the imaging characteristics of GCTTS clearly, it can provide reliable evidence for clinical diagnosis and treatment, and can help doctors make correct judgment and therapeutic schedule.