Objective To explore the differential value of clinical features and MRI in differentiating idiopathic granulomatous mastitis(IGM) and non-mass enhancement of breast cancer.Methods The clinical features and MRI findings of 45 cases of IGM and 57 cases of non-mass enhancement of breast cancer were analyzed retrospectively in the study.All patients were examined by routine MR scan and additional DCE and DWI scan.The difference of clinical and MRI features in 2 groups was analyzed by χ2 test.One-way ANOVA was employed to compare the ADC values between different sites of IGM and breast cancer.Results There was statistical significance between IGM and breast cancer in age at onset, enhancement pat-tern, mastalgia, nipple retraction, and thicken skin (P<0.01).The abscess area of IGM showed ob-viously hyperintensity on DWI, the non-abscess area showed hyperintensity.The lesion of the non-mass enhancement of breast cancer showed hyperintensity.There was statistical significance of ADC value between the lesion of the non-mass enhancement of breast cancer and the non-abscess area of IGM(P<0.01).Conclusion Clinical and MRI features have a certain value in the identification of IGM and non-mass enhancement of breast cancer.