The areas of Nigiwai-machi, Ohji-cho, and Hannan-cho in Osaka city, Japan are residential areas composed of wooden rowhouses, which were spared from air raids in World War II. Recently, these areas have been losing their distinct social and physical character, due to their replacement by new detached houses and apartment buildings. Especially, outdoor activities have greatly decreased. These are not only traditional characteristics of these areas, but also opportunities to form communities. It is necessary to discuss methods to renew or maintain these areas by clarifying changes in outdoor activities and environmental conditions influencing these activities. This study consists of two parts; one is a quantitative analysis on changes in outdoor activities by comparing the behavior mappings conducted in 1973, 1985 and 2000. The other is a qualitative analysis of the environmental conditions having an effect on outdoor activities by thorough investigations of the streets where many outdoor activities can still be observed in 2000.