Objective To investigate the features and diagnostic value of magnetic resonance imaging (MRI) in demyelinating pseudotumor of central nervous system. Methods The imaging data of 15 patients with demyelinating pseudotumor of central nervous system (confirmed by clinic or pathology) who treated from June 2010 to June 2017 were analyzed retrospectively. Image features of MRI scan and enhanced scan were summarized. Results Findings of MRI scan showed intracranial lesions in 12 cases (including 7 cases of solitary lesions, 5 cases of multiple lesions) and cervical spinal cord lesions of C2-C5 level in 3 cases. The average diameter of solitary lesions was (3.89±1.45) cm, and cervical lesions were stripped. The lesions were irregular in 10 cases, quasi-circular or oval in 2 cases. The boundaries were clear in 9 cases and unclear in 6 cases. There was mild edema around lesions in 12 cases. MRI signal and features of enhanced scan showed long T1 and long T2 signals in 12 cases, equal T1 and long T2 signals in 3 cases. There was no cystic change or calcification. There was ring enhancement in 4 cases and semi-open ring enhancement in 2 cases (ring opening sign and vertical sign) after enhanced scanning. Conclusion The typical features of MRI enhanced scan like ring opening sign are of certain value in the diagnosis of demyelinating pseudotumor of central nervous system.