Progressive supranuclear palsy (PSP) is an atypical Parkinsonism but with a faster progressive course. Previous studies indicated that PSP patients showed not only gray matter volume decrease but also white matter tract degeneration. We use fixel based analysis to examine the difference in the fibre bundle (FD), fibre-bundle cross-section (FC) and combination of fibre density and bundle cross-sectional area (FDC) between patients with PSP and healthy controls. The results show that significant degeneration of white matter in PSP patients. The major advantage to this study is providing a fixel-based comparison that indicate more directly interpretable measures of structural integrity.