Objective:To analyse the shape,fiber structure of normal adult cerebral corpus callosum in living humans by using diffusion tensor tracking.Methods:10 healthy adult volunteers (5men,5 women;age range,24~65 years; mean age 40.9years) were examined with MR diffusion tensor.All data were transferred to a personal computer and were processed with dTV(Tokyo University,Japan).Results:The corpus callosums of all volunteers were observed three dimensionally.The corpus callosum showed lune shape on color sagittal fractional anisotropy map and centipede shape on axial diffusion tensor tracking map.Conclusion:Diffusion tensor tracking is useful for showing the normal adult cerebral corpus callosum, and open a new field for researching cerebral white matter fiber in vivo.