When did observation in territory at corridors of Buddha Tzu Chi flats, relationship between territory and territoriality of flats dwellers could be seen. There are two types of corridors. There is a larger corridor flanked by three blocks of flats, and there is smaller corridor inside the block of flats, and flanked by four units of flats. When did observation in territory at the large corridor, many territoriality of flats dwellers were seen there. However, when did observation in territory at the small corridor, territoriality of flats dwellers were not much to be seen there. Both corridors are not only differ in terms of size, but also differ in who is accessing territorial zone formed therein. So that needs to be further researched whether the relationship between the territory and territoriality lies in space scale of the territory, or accessibility of territorial zones in the territory, or other aspect contained in the territory. How is the relationship of territory and territoriality in corridor at flats becomes problem question in this research. Methods of data collection in this research using the technique of selfobservation and interview. Self-observation was conducted to know the characteristics of the territory in the corridors of flats and territoriality of flats dwellers in the territory. While the interview was done to increase the validity of the data obtained from self-observation about territoriality in territory at the corridors of flats. The research concluded that there is a relationship between territory and territoriality in corridor at flats. That relationship influenced by the characteristics of the territory in the corridor at flats, such as space accessibility and constraints of the territorial zone formed therein.