Objectives: Urban population of Sistan and Balouchestan province in two recent decades for many reasons such as rural and urban immigrations and to change many villages to city points has made many intensive revolutions. At the result disintegration dispersion urban regions and disequilibrium in urban hierarchy organization and appearance of primate city is carried out. Due to the capital- oriented policies adopted by the Iranian officials, Zahedan the capital of Sistan and Balouchestan province has maintained its superior position over other cities of the Province froml 956 to 2006. Therefore, no balancing programs have been determined to develop the appropriate urban spaces so for. As a result Zahedans population is now more than the total population of the vest of the Province with the pioneer specialized, economic and political facilities present therein. Method: Research method is combined of documental, descriptive and analytic methods. In this research, the required information and the population data were collected from the valid resources via library methods. Then using the Zipf rank- size model and patterns, the statistical model of levels difference limit and the Lorenz curve, the quality and quantity analyses were carried out. In order to process the data the Mat lab and Excel software’s were used. The goal of this paper is investigation and analysis of urban hierarchy organization, reasons of population fast growth over many of cities, arise problems from disordering in urban hierarchy organization and offering ways for reforms over urban organization of province. Findings: Study findings show that urban hierarchy organization of Sistan and Balouchestan province in 1986- 2006 decades is very disequilibrium and is from primate city type. The finding showed that between 1986- 2006, Zahedan had been the dominate city in the Province. Bang the capital and enjoying welfare services and commodities such as health, military and higher education centers along with the immigrations from neighboring villages and cities have made the population of Zahedan larger. Thus the development of the “Primate City” phenomenon. According to the Lorenz curve model, the differentiation coefficient of the cities of Sistan and Balouchestan province unbalance during 1986- 2006 which indicates the phenomenon of unbalance in the urban hierarchy in the province. In addition, it changed from semi-equilibrium to critical point in 2006. Results: According to for going patterns and models, inequality and imbalance can be obviously observed. The of the urban hierarchy system shows that the vast gap existing between the provinces primate city and the other cities which has caused the imbalance and the cities going faraway from the balance line. The increasing number of small cities during 1986-1996 has contributed to the imbalance in the hierarchical system of the province cities. Small cities apart from being much scattered and geographically remote, lack the appropriate local commodities and potentials. If not noticed sufficiently, small cities will lead the urban hierarchical system of the province to a crisis. In general paying attention to small and middle sized cities and the increase of capital, commodities and services to them, will decrease the local imbalance and will lead the urban hierarchy of the province to balance in a large time.