Due to its size, the city of Zabul is facing the phenomenon of marginalization. The reason for the spread of marginalization is the increase of welfare facilities in the city, the release of agricultural, livestock, drying of the Helmand River and Hamoon Wetland, the closure of the border and the lack of development of border markets in villages and their unemployment due to lack of positive economic view by policy makers. Sistan has upset the balance between the city and the countryside, which has led to migration to the city, as well as poverty, unemployment, cheap property, rent, land in the suburbs and the lack of green space in the main areas of the city has led to many problems, including informal housing. . Therefore, this study was conducted in response to the question, what are the reasons for the expansion of suburban areas of Zabol city and regional planning based on problem control? Qualitative research, based on theme analysis and information tools required for this research. Literature review and theoretical foundations of research, documents, field observations and exploratory studies of the author and semi-structured interviews with 20 elites about the comprehensiveness of the classification of indicators. After analyzing the data, economic and environmental themes and lack of proper rural development policy in Sistan region as the cause of the expansion of suburban areas of Zabol city and prevention at the origin (villages of Sistan region) and prevention at the destination (Zabol city) to The titles of regional planning based on curbing the spread of marginalization were identified and discussed