In this study, we want to analysis the Urban network and the spatial distribution of  the population in the urban centers of the province during the years 1335 to 1390. Analytic - descriptive method is applied as the chief method in this practical study. The data were collected from the Statistical Yearbooks of Khuzestan. The collected data were analyzed by using software program EXCEL,along with rank-size rule methods ,logarithm distribution ,limit of class diffrennce, Entropy Coefficient, Elasticity Coefficient, we take to surveying about the condition of Urban network,city  hierarchy and spatial distribution of the population in the khouzestan province. durig this years, two period have been identified.the first period, includes the years of 1335 to 1355.of the characteristic in this period,we can point to the lack of primate city, relative equilibrium in the distribution of  population in Urban classes, the number of  big cities and centralization of the most  part of population in them, the lack of existence of the excellence of ahvaz to big cities of the province and a very few number of small cities. The second  period  includes the  years 1355 to 1390. With the attack of Iraq to Iran in the year 1359, a turning  point a ccurs  in the Urban  system of  khouzestan  province. This war  led to the evacuation  of  population in  two big cities, namely Abadan and  khorramshahr and also to many  changes of  population in the Urban system of the khouzestan province.during this period, the Urban network of khouzestan  province has been out of equilibrium. The primate city is on the rise.Ahvaz  separates itself from other cities and To become a metropolis of millions. the number of small cities strongly increased.