Polycentric urban regions (PUR) are the answer to balancing and addressing the shortcomings of the monocentric model. In the polycentric model, centers with relatively equal spatial and demographic sizes that are spaced a short distance apart form cohesive assemblies and, with the benefit of energy synergy, complement each other with competitive activities. The cities of Sari, Babol, Amol, and Ghaemshahr are among the main centers of Mazandaran province; But despite having the features of a polycentric model, there have not been many joint synergistic and competitive activities that lead to the development of the region between the centers. In this regard, the present study, with the help of flow analysis method, gravity model, and also calculating the connection strength between the cities of the province and the main centers, has provided an area for the polycentric urban region of Mazandaran through which to plan for this area. And bring progress to the region. The final boundary of the PUR of Mazandaran has been delineated and presented by ArcGIS software by examining the determined indicators according to theoretical bases and information obtained from the current status recognition section. This area includes the cities of Sari, Ghaemshahr, Babol, Amol, Imamzadeh Abdullah, Dabudasht, Zargar Mahalla, Gatab, Amirkola, Hadi Shahr, Kiakola, Joybar, Arateh, Pa'in Holar, and Miyandorud.