Objective To observe the MRI characteristics in subacute combined degeneration (SCD)of the spinal cord.Methods The data of 1 9 SCD patients were retrospectively analyzed by the clinical characteristics and MR images.Results Among the 1 9 pa-tients of SCD,1 6 cases showed abnormal findings.Most of intramedullary lesions located in posterior column of thoracic and cervical spinal cord,and only one case located in cerebellar cortex and medulla oblongata.Lesions were involved in muti-segmental spinal cord,and mainly located in the dorsal or lateral spinal cord,and only two cases located in the anterior spinal cord.Different segmental spinal cord lesions had a different morphological characteristics with no enhancement.After treatments with vitamin B1 2 ,the lesions diminished and even disappeared in 2 cases.Conclusion MRI has important value in the diagnosis and treatment monitor of the SCD.