Purpose of the study: Social capital is one of the issues that creating, maintaining and enriching it is one of the main goals of sustainable urban development. The sense of belonging to the place in the inhabitants of each neighborhood leads to the formation of a place identity, which affects the sense of belonging to popular participation and social capital, the analysis of which is the purpose of this article. Methodology:In this research, based on the Cochran formula, a sample of 371 inhabitants of the informal settlement of the city of Sari who is involved with social problems is selected as sample and each of the variables of the study, which is the sense of place belonging, popular participation and capital Social, using the correlation method, and then, using structural equation models, two models of how different relationships were made between variables. Main Findings:The results show that the influence model of the sense of belonging to social capital increases through the mediating variable of popular participation better than the rest of these relationships, in other words, in an indirect causal relationship, the strengthening of the sense of belonging places increases participation And increase social capital. Implications of this study: It is imperative that urban planners and planners are targeted at planning in relation to these neighborhoods, social capital and place of gratitude, and in order to maintain social trust, especially the people's trust in urban management, which is one of the most important aspects of social capital, as well as the sense The attachment and attachment of people to their place of residence. This study, by clarifying the nature of this relationship, helps local planners and decision makers to better understand these two variables. Novelty of this study: The sense of belonging to neighborhood will lead to more citizen participation, and participation will also increase social capital. So, it can be said that having societi
