Tabriz metropolitan is the largest living complex of north west of Iran, which contains a very vast influential realm due to its locational situation. Because of political centralization, and the concentration of administrative, industrial, economic, and university activities, as well as higher level of expertise, specialization and services establishments, Tabriz plays the role of an attractive pole and primate city and a macro-cephaly in the region. For these reasons, its expanse is increasing continuously. During the recent decades, the city has undergone an irregular and rapid growth, and has experienced incredible population and spatial changes. Accordingly, the present article has been paid according to the spatial development of Tabriz between the years 1335-85 and analyzed the unbalanced development pattern in spatial extension. Results of this research show that the population increase, excessive in migration, hence the spatial development and distribution of the city have resulted in the deficiency and expensiveness of land and settlements, destruction of orchards and farm lands, oldness and evacuation of fabric texture, the reduction of cultural values and historical identity of city, handing over the unstable and potentially dangerous areas, deterioration of aesthetic aspects, appearance and expansion of shanty dwelling, emergence of surrounding villages and their changing roles, all threatening environmental efficiencies of the city. On the other hand discordance of spatial development of the city with the capacity of infra structures and urban spaces, and in other words, lake of the dominance of urban planning lawful programs over city extension has led to underdevelopment of city construction and has raised critical question on urban sustainable development.