Street-in-the-air has been regarded as a device which supplements the defects of high-rise blocks. It should be, however, noted that most of street-in-the-air has been based on the concept of urbanity in the automobile era as well. Based on this point of view, the 5 types of approaches to the street-in-the-air in this paper were introduced. Throughout the research, it was figured out that the types of approaches focusing the urban spatial system tended to neglect the essential properties of street itself as place for everyday life. In considering that street is defined by relationship with building or units, it is necessary to secure the correlation of street-in-the-air with units prior to considering the urban spatial system.