The purpose of this investigation is to reveal the possibility of urban small green space on building roofs and sites providing for the urban ecosystem. On that account we grasped the characteristics of these green spaces and the actual situat ion of bird distribution in Osaka City. From results of the investigation, the relationship was verified by using correlation analysis and multiple regression analysis. In consequence, it was found that the biodiversity tends to improve as the amount of green increases, and the impact of shrubs is particularly strong. In addition, Horomis diphone and Aegithalos caudatus were influenced by the presence of certain trees. Furthermore, the influence of the internal environment on the birds was mainly confirmed in these green spaces but the external environment was not much. Based upon these results, the stratification of plants was important on narrow urban green spaces, especially on the rooftop green space. This study has shown that improving quality of internal environment influence bird distribution in these green spaces. At last, making such green spaces and their connection may contribute to the urban ecosystem.
