The purpose of this study is to define the concept of Hilly/Mountainous and Less-Favored Areas from the viewpoint of agricultural infrastructure, and to establish selection criteria and categorize of that areas. Using three type guidelines which were the rates of forest(above 50%), farmhouse population(above 50%) and infrastructure improvement(below 50%), the regions of 605 Eup Myon were selected to Hilly/Mountainous and Less-Favored Area. And for applying to regional development planning, the legions of eup myon were classified 4 types using average of the rate of forest and aged farmhouse population(75%, 17.5%). To conserve the farmland in Hilly/Mountainous and Less-Favored Areas, it requires continuous research on systematic approach method. Especially, it is necessary to investigate a development formula according to farmland scale and desolated degree through analysis of the actual condition of farmland.