This study aims to offer basic data for development of the three generations sharing house plan, through finding out the relationship between family characteristics and the housing needs of the middle aged living in the middle and small cities. The 1029 questionnaires were used for this study, and data were analysed by canonical correlation analysis, factor analysis and multiple regression. The results are as follows. Their family characteristics influence housing needs for the three generations sharing house. Especially groups of female, neuclear family, family of higher S.E.S., less number of children. family living in the apartment houses and owner occupied house prefer more privacy between generations in the three generations sharing house.