The multi-sectoral nature of water management requires cooperation and coordination between actors involved in water governance. The integrity of the water governance network requires the existence of trust between these actors to strengthen communication and interactions between them. This study was conducted to analyze the water governance network in Mazandaran province from the perspective of inter-institutional trust and interaction. In this regard, first, 21 institutions and organizations were identified through archival research, direct observation, and unstructured interviews with experts and activists in the field of water governance in Mazandaran province, and in the next step, to analyze the structure of the pattern of relationships between these institutional activities, social network analysis approach was used. The results of the research showed that the inter-institutional trust and interaction at the level of the water governance network of the province is average, and therefore the communication between the actors of this network is not easily done. Key organizations such as the regional water company, agricultural jihad, and governorate are in an important position at the level of the inter-institutional trust and interaction network, and they play the role of intermediaries. Based on the results of this research, strengthening the trust between water governance actors and their interaction as much as possible at the levels of policy, planning, implementation and monitoring of water projects can improve the coherence of the water governance network of Mazandaran province