Objective To analyze the MRI features of idiopathic granulomatous mastitis(IGM) and to improve the preoperative diagnostic accurancy of IGM. Methods A total of 16 patients with pathologically-proved IGM, who were encountered at Fujian Province Cancer Hospital during the period from Jan 2014 to Dec 2017, were enrolled in this study. Breast MRI examination was performed in all patients．According to Breast Imaging and Reporting Data System Magnetic Resonance Imaging(BI-RADS-MRI) standard, which was proposed by American Radiological Society, the MRI manifestations, including morphology, signal intensity on plain T1WI and T2WI, dynamic contrast enhanced MRI(DCE-MRI), the pattern of time-signal intensity curve(TIC) and apparent diffusion coefficient (ADC) values, were retrospectively analyzed. Results The lesions of 16 cases located in unilateral breast, 11 cases on the right breast and 5 cases on the left. All of them presented iso-intensity and hypo-intensity signal on T1WI, and presented heterogeneous hyper-intensity signal on fat suppressed T2WI. On contrast enhanced MRI, the enhanced lesions showed mass-like enhancement in 9 cases and non-mass like enhancement in 6 cases, all of the enhanced lesions appeared as unclear edge and cystic areas. 14 lesions presented with fast enhancement in 2 minutes, and the TIC types presented as inflow type, insistent type, and outflow type in 1, 10 and 3 lesions respectively. 13 cases showed nipple involved and skin thickening. 5 cases showed fuzzy fat gap between lesion and pectoralis major. There were 13 cases with supplying arteries dilated. 6 cases with ipsilateral axillary lymph nodes enlarged. ADC values ranged from 0. 87×10-3mm/s to 1.97×10-3mm/s in 14 cases. Conclusion The DCE-MRI and TIC curve combined with morphology and clinic data, can help to improve the preoperative diagnostic accurancy of IGM.