The main space in which historical and political conflicts of societies can be observed is city. As politics and economics are the fields of acts fundamentally belonging to city, the size of the social conflict and division which are directly related to these two fields can be discovered through the structure of city. The object of this study is to search for the roots of primordial urban social divide through common characteristics of central pagan Roman cities. This study generally progresses through central Rome, though it includes the common characteristics of Rome, Neapolis and Pompeii.The main determinant of Roman daily life was the city itself as was the case in Ancient Greece. The city, for the empire, was not only an allocation unit that the people lived in, but also a space in which political and economic works were carried on; and also an apparatus that was used for passing on Romanness to future generations and spreading out Roman culture and its religion. The physical being of city is to materialize the difference between the people lived in the city and the peasant who lived outside the city and who also were the real productive forces of economy. This difference can be seen in all components that makes a city for Romans.The nature of social divide has become permanent for post-Roman era. Spatial units, as reflectors of the divide, have contained same structural characteristics under different appearances through the ages. Moreover this spatial differentiation remained valid for modern cities. In this respect, analyzing the units of urban space may be useful to analyze the nature of social antagonisms.