The objective of the present study is to clarify how important it is for older adults living in the mixed care house to have interaction with children. The study articipants are a total of 10 elderly persons including three males and seven females living in the mixed care house. The semistructured interview method was used to collect data. The data obtained were subjected to qualitative and posteriori analyses. The analytical results showed that, for the older adults living in the mixed care house, interaction with children was important because this experience helped them recognize ‘comfortable living environment,’'enhanced energy to live,’‘improvement of self-esteem’ and ‘look back upon individual life.’ Thus, the interaction with children itself provides ‘comfortable living environment’ for these older adults. This environment promotes ‘enhancement of energy to live’and ‘improvement of self-esteem.’ Then, they can find ‘look back upon individual life.’ The results suggested that these older adults could promote integrity, a development task in old age, through accumulated experiences of daily interaction with children attending the nursery in the mixed care house.