High buildings can have a multiplicity of functions. Their role is increasing more and more in land use of the city region. Recently, because of rapid increase in residential buildings, the residential structure of the whole city is changing. Residence in condominiums and apartment houses is a new life style in Japan, because traditionally Japanese did not have a habit of dwelling in high-rise housing. The characteristics of residents in residential buildings vary in relation to housing occupancy, the quality of house and so on. The purpose of this study is to clarify the development process of condominiums and the characteristics of the residents in residential buildings. The results of this study are summarised as follows:1. In Hiroshima City, there are some areas around the city center in which population showed an increase in the period 1975-80. Because private developers constructed many condominiums in those areas, there was an increase in home-owning households in the neighbourhoods of city center. After 1978, new condominiums which were constructed by private developers are concentrated in a 1-2km zone from the city center. In the central city regions, many offices, stores, and parking lots were converted into condominiums. On the other hand, in marginal city areas many warehouses and housing estates were converted into condominiums. The location and quality of condominiums vary according to their developers.2. Using the 1970, 1975 and 1980 Population Census of Japan, it was found that the structure of age, household members and occupations of residents varies according to the kind of housing. So a kind of segregation appears. The characteristics of residents in condominiums, public housing and company housing for employees are different.In private housing, there are rental housing in which many younger households with a few members reside and resident-owned housing in which many middle-aged households with 3-4 members reside. Many of these residents are engaged in white collar occupations. In public housing, there are many elderly people, especially in older units which are located near the central city area. And the ratio of elderly people who rent old public housing is increasing. By contrast, in new public housing in the suburbs the residents tend to be younger. Many of the residents in public housing engage in blue collar occupations. Blue collar workers living in company-provided housing tend to be younger than the civil servants living in officially-provided housing.It is thought that the in crease in condominiums in the inner city is inducing gentrification because residents of condominiums are white collar workers with a high socioeconomic status.3. By obtaining information through questionnaires given to residents in 34 samples of condominiums which were selected randomly in the old city region of Hiroshima City, the characteristics of the residents were clarified.There is a tendency for people to decide to migrate in order to increase their living space or because of work transfers. When they purchase a new house, they think much about living space, the convenience of traffic, access to their work place and convenience of shopping rather than the overall environment of the neighbourhood. People generally relocate a short distance, but there are variations in this pattern according the age and district.As is mentioned above, it is thought that development of condominiums will play an even greater role in urban renewal in the near future. So it is important to analyze their development process and the characteristics of their residents.