The demand for one-room system house as a new type of house will increase gradually, and residents also tend to be diversified. However, a method of planning of planning of one-room system house was limited and unified. Current floor plans of the one-room don't utilize a benefit of open plan in small areas. The purpose of this study is to propose several guidelines for the planning of one-room system houses that correspond to residents' needs in order to facilitate the benefit of open plan such as efficiency and multi-purpose use in small area. For this, a field survey was carried out as case studies, with individual interviews, questionnaires, and actual survey including taking pictures. Subjects were 50 residents who living in one-room system houses in Busan. Space usage behavior of residents, residential satisfactions, and preference attitudes on the attached service facilities were analyzed. The results were synthesized to suggest several guidelines for planning of one-room system house.