There is a word called ‘Hospitalism’. Living at closed institutional settings causes this condition to residents. They tend to become passive and inactive, and to lose spontaneity and attention to others. To prevent this condition, it is said that residents should keep privacy, be encouraged to act by their own decisions, live in a home-like atmosphere, and have frequent contact with community. These factors correspond with the Japanese new standard for nursing homes. In Japan, according to the rapid increase of the elderly, a number of nursing homes have been constructed in decades. But recently quality has been focused and emphasized. Since 2002, to improve the quality of nursing homes, the all new-built nursing homes have been obligated to consist of single rooms and separate rooms into some groups in order to make a home-like atmosphere. The institutions made a big step forward.The subject of this study was residents who moved from the old assisted living into the new one. Their ADL levels were relatively high, and their dementia levels were mild, and so effects of the care conditions had little impact. Therefore, they were appropriate for the subject of investigation of the relationship between behavior and environment. This study focused on resident-behavior’s changes according to moving into the new assisted living. At the old one, residents had to share rooms, and common spaces were not ample. At the new one, each resident had his/her own room, and 50 rooms were separated into 6 units, and each unit had a dining room, a living room, a bathroom and so on. To analyze the changes, the behavior tracking survey and the interview were carried out at the old home and the new one.At the old one, during one-third of a day time residents were doing nothing special and spending time idly. These idle lives were observed not only at residents’ rooms but also at common spaces. At a chatting room, residents killed time rather than had communication with other residents. They tended to stay at common spaces including the chatting room, because they did not want to stay with his/her roommate. They could be divided into 4 groups by the type of behavior and places where they stayed, that is, active behavior at the resident’s room, passive behavior at the resident’s room, active behavior at the common spaces, and passive behavior at the common spaces. Comparing between men and women, men spent more time in hobby, like reading books, gardening and so on, and on the other hand women spent more time in housekeeping, like cleaning rooms, washing clothes and so on. By moving into the new one, residents’ behavior changed. They became more active and tended to engage into more activities. Women spent more time in housekeeping, especially preparing meals and clearing the table, because the each unit had a home-size kitchen. They chose spaces depending on activities, that is, when they wanted to take a rest, they tended to stay at his/her room, and when they wanted to have contact with others, they came out from his/ her room to the common spaces. They tended to keep their activities longer inside rooms because they were not interrupted by roommates. They visited other residents’ rooms more frequently and stayed there longer. They paid more attention to others. This had 2 effects, namely, the good one and the bad one. They took care of other residents more frequently, but at the same time, the number of troubles among residents increased. Staff was expected to play a more important role in controlling the relationship among residents.Most residents became more active and tried to have more frequent contact with others at the new home, but some residents spent most time idly as before. The improvement of the built environment, of course, enriched their lives, but it was not the perfect answer. They should be encouraged to play their own roles in the home, and also in community.ReferenceBarton, R., Institutional Neurosis, 3rd ed. 1976.