Diffusion Tensor Imaging (DTI) can detect diffusion information of water molecules, and is used to diagnose the severity of degenerative cervical myelopathy (DCM). However, the diagnostic capability of DTI metrics is not fully investigated. In this study, DTI metrics are employed to evaluate the spinal cord function in preoperative DCM patients and healthy volunteers. Nonparametric t-test results show that MD, FA and RD have significant differences between patients and healthy volunteers. In addition, ROC results indicate that FA has higher sensitivity, RD has higher specificity for evaluation and diagnosis in DCM.