The metropolis phenomenon is one of the phenomena of the twentieth century (in particular the second half) and the third millennium. After the industrial revolution and the progress of its progress (especially the progress of transport and widespread use of the car), in the way of urban lifestyle, the fundamental changes were created that the urbanization and transformational growth in the role, performance and structure of the cities are among these changes. The process of creating metropolis and changes in them in different countries is influenced by various forces and factors that usually work differently. In Iran, several factors have been effective in the creation and growth of metropolis. Some of the urban care ermen are the beginning of the Reza Khan government to begin the basic developments in the city of the city in Iran. In this period, the fundamental physical changes in cities (especially cities with a history of cultural and historical backgrounds) were created and the context for the next developments influenced by modernism, the polar theory of growth and national and regional projects and the measures taken according to them, caused the basic developments in the Iranian regulatory system. This paper has been described by descriptive-documentary and use of various sources and the aim of recognizing the process of formation and development of metropolis in Iran.