Dementia care has become one of the major social issues in developed countries including Japan. Dementia currently affects more than one million Japanese elderly people. About 75% of people with dementia stay in home, mostly being taken care of by family members. The remaining 25% are eared for in nursing homes, geriatric hospitals and other related facilities. Besides those conventional types of the environment, innovative facilities of group living have been recently built in homelike setting. The study illustrates environment-behavior study in one of the models. The new model has several group living units. Each unit has 10-12 residents. The behaviors related to dementia such as wandering, disturbance, acting out, were compared the three months data with the one year data after becoming residency. The frequency and time spent in such behaviors significantly decreased, especially wandering behavior. There were also significant differences among degrees of dementia. The study suggest that group living units are invaluable in terms of decreasing confused behaviors.