"Purpose: The purpose of this study is to improve sustainable environment for persons with dementia in more homelike, in which the study is based on the characteristics of environmental behaviors for persons with dementia and staffs, psychology for staffs and artifacts in activity spaces and private rooms of nursing home.Background: Living environmental issues for persons with dementia have become more and more important. How can improve the living environment for them to homelike is paid to attention as an important theme decreasing their uneasiness and confusion, and stabilizing their mental status in recent years. However, because a concrete standard to the homelike is not shown, persons with dementia living in nursing home and staff are confusing now. Therefore, it is necessary to clarify a concrete standard for creating the homelike environment in the nursing home immediately. Method: The surveyed nursing home to which the group care is practiced has the conventional living and the group Living. In the conventional living and the group Living, four and three respectively group care units exist. We surveyed all the group care units to clarify the environmental factors for creating the homelike. The main three surveys were executed. 1) The person-environment transaction was analyzed by behavioral tracking method to all persons with dementia living in the nursing home and all staffs. 2) The degree of homelike with twenty-one activity spaces and private rooms respectively was analyzed by semantic differential method to twenty-three staffs. 3) The kind, the number, and the process of bringing to all artifacts in twenty-one activity spaces and private rooms respectively were interviewed from persons with dementia and staffs. Results and Conclusions: We find that the important environmental factors creating more homelike for persons with dementia are "human scale", "familiarity" and "personal life". However, these important degrees are different between the activity spaces and the private rooms. The degree of importance increases in order of human scale < personal life < familiarity for the activity spaces and human scale < familiarity < personal life for the private rooms. Therefore, it is necessary that the activity spaces changing rapidly by a lot of person's gathering are designed to feel familiarity more for persons with dementia. On the other hand, it is necessary that the private rooms with familiar more compared with the activity spaces are designed positively to lead personal life more."