Objective To analyse and summarize the MRI characteristics of tumor‐like inflammatory demyelinating diseases (TIDD) .Methods MRI findings of 10 cases with pathologically proved TIDD were analyzed retrospectively ,all patients received plain and enhanced MRI scan .Results 3 cases showed multiple lesions in bilateral frontal and parietal lobes ,and 7 cases showed soli‐tary mass ,in which 2 lesions located in the occipital lobe ,2 in the basal ganglia ,2 in the second to fifth segment of cervical cord ,and 1 lesion located in the left frontal parietal lobe .The shape of 7 lesions were irregular ,2 were stripped ,while 1 lesion was oval .6 cases had clear boundary ,while 4 showed ambiguous .Solitary lesions were 1 .7 cm -5 .6 cm in diameter(mean 4 .0 cm ± 1 .48 cm) .8 cases manifested mild edema while 2 had no edema .On MRI plain scan ,lesions were hypointensity on T1WI and hyperintensity on T2WI in 8 cases ,isointensity on T1 WI and hyperintensity on T2 WI in 2 cases ,and all lesions were hyperintensity on FLAIR sequence .DWI were performed in 3 cases ,all lesions showed hyperintensity ,2 of them had patchy hypointensity signal .Hemorrhage was detected in 3 lesions ,cystic lesions or calcification were not found in all cases .On post‐contrast scan ,3 lesions showed ring like enhancement ,2 showed obviously heterogeneous enhancement ,2 had mild enhancement and 2 cases had no enhancement ,1 presented with open ring like enhancement .Conclusion TIDD shows some specific MRI features ,and MRI is helpful to the diagnosis of TIDD .