The purpose of this study was to investigate spatial characteristics and using behavior of activity room in skilled nursing facilities for the elderly and to provide basic guidelines about its space planning. The activity rooms in the most of the research facilities were arranged by usage modification of unnecessary spaces after the foundation of the facility, and were used not only for the program service but for the staff lounge. It decreased space speciality and resulted in limited area of the space and crowded furniture arrangement. The design guidelines for activity room were as follows. First, the space plan of activity room is based on the use of once to twice per week and for 30 minutes per use, and is mainly for the human knowledge and art programs that are appropriate for small group. Second, the activity room of the facility with less than 3 stories needs to be in the same floor as elderly individual room, but should be independent and easy to be controlled by the staff. On the other hand, in more than 4 stories facility, it is better to be in the different floor as the elderly living area such as administrational area close to the lounge and garden. Third, at least $5.9m^{2}$ per user for the area of the activity room is recommended including the elderly, staff, furniture, equipments and restroom. Fourth, the furniture of activity room includes the shelves, big table with enough knee space, wheel, and stopper, and stackable chairs. Toilets and water closet are needed for the emergency, and the windows to the corridor and curtain door should be avoided for soundproof and easy access of wheelchair users.