The emergence, formation and evolution of drainage network patterns in the bed of a catchment are known as a geosystem identity. In this research, we have used Order Matrix model in three basins, including: Beshar Basin, Seymareh Basin, Ramhormoz Basin (southwest Iran). The Order Matrix model, as a valuable tool examines and analyzes river networks, regardless of their size, and presents the degree of irregularity of river networks. In this regard, the vector data of the streams obtained from the topographic maps of 1: 50,000 were processed in ArcGIS software to analyze each of the right and left parts of the research area. The results of Order Matrix model show that the pattern of drainage network of Beshar basin is not the same in the right and left parts and hierarchical order is low in the basin. Tectonic situation in Beshar basin has been the main cause of inequality in the region. Tectonic condition and uneven rock strength in Seymareh basin has been the main cause of inequality in the basin. In Ramhormoz basin, the number and length of waterways on the left side of the basin is increasing compared to the right, and the lengths of waterways are not balanced in any of the categories. However, the research has indicated that the model can accurately analyze the inequality and fluvial dynamism and behavior in the watersheds.