Primary purpose of this study was to examine the process of landform transformation for the new town development in the suburban hilly topographical areas, and the concepts and ideas of physical planning and design in its background as well. A case study was conducted in Senri New Town that extends across the area of Suita City and Toyonaka City, Osaka Prefecture. Based on the information found in graphical plans and project reports, and following three steps of project level, i.e. project planning for the entire area, planning of each individual area and layout design of each residential block, how the original topography was integrated into the landform and landscape planning was closely traced. Although the topographical features was given a higher priority on the level of project planning and numerous methods to adopt topography to landform design were employed, those have been dismissed in the later steps of project due mostly to time constrains and innovations in civil engineering technology. On the other hand, substantial endeavors were given to planning and designing prominent residential environment by integrating topographical features on the level of developing each residential block