This study examines the relationship between biodiversity and the housing value of residential areas in downtown Tokyo, and reviews the history of green space planning and surveys of present residential attitudes towards green space in the metropolitan area. Throughout the research, biodiversity is operationally represented by a “green coverage ratio”, while standardised data on land and rent prices are used to assess the value of residential areas. The results confirm that the green coverage ratio and housing value are correlated. The study concludes that there is a need for development of a more accurate and integrated policy database that will provide explicit definitions of management targets, locations and clients for promotion of green space in Tokyo.