Chronic spinal cord compression induced cervical myelopathy is a comon cause of spinal cord dysfunction. The exact mechanisms of underlying progressive cell death remain to be elucidated. In this study, in vivo diffusion tensor imaging (DTI) has been applied to investigate the microstructural changes of white matter (WM) in this neurodegenerative disease. Compared with conventional MRI techniques, DTI is believed to be more specific to pathological changes. Radial diffusivity (lambda upper left and right quadrants) is higher in the ipilesional region, suggesting demyelination or axonal degradation may occur after prolonged compression. Near the epicenter of lesion, axial diffusivity (lambda(//)) is lower. Also, caudal-rostral asymmetry has been observed in lambda(//). Feasibility of using DTI to detect microstructural changes in chronic disease has been demonstrated.