A survey was conducted of the regional distribution of the Japanese giant flying squirrel, Petaurista leucogenys, in the six hilly areas of Southern-Tama district, Tokyo. The results of the survey were overlaid the land cover map derived from LANDSAT data. Fragmentation of wood land, type of vegetation cover, and area of habitats were determined quantitatively using GIS. It was confirmed that there is fragmentation of the habitats of the Japanese giant flying squirrel for example the woodlands in the Tama hilly area. We suggest that continuous woodland over areas equivalent to the average range of the Japanese giant flying squirrel is required to ensure sustainable population within the habitat, and that isolation and fragmentation of woodland has a significant influence on the sustainability of the habitat for this species. In the woodlands of the hilly areas of Southern-Tama district, where deciduous trees are dominant, it appears that the higher proportion of evergreen trees than the local average improves the value of the habitat for the Japanese giant flying squirrel.
