ملخص الدراسة:

The demographic diversification is a distinguished character in the great cities. Vertically, the diversification dimensions lie in the expansion of the gap between the top and base of the economic pyramid. Horizontally, the diversification is caused by the ethnic, religious and tribal differences. The research will not deal with the first aspect, but it will be satisfied in dealing with the second one only, as an applied on Mosul city, which is considered as a population polarization center of the hinterland areas, which is distinguished by diversification in the second aspect.The diversification character is not considered as an urban problem, when the urban administrative system is rigorous. But it seems to be a real problem, when the city loses the executive venaration, then, population of the hinterland areas who settle inside the city, has become a fifth battlion for the start off area. The research tackles by analysis the diversity justifications, and the reactions which reflect on the urban life in Mosul city.