One of the methods and approaches that have been proposed for urban development planning is strategic urban development planning, in which the process of paying attention to social and institutional capacities on the one hand and localization as a process that, in accordance with urgent needs and current conditions, draws issues, topics, and solutions from the knowledge of different cultures and civilizations; on the other hand, is important. In this regard, the main goal of this article is the localization process of strategic urban development planning with an emphasis on institutional and social capacity indicators in the city of Karaj. This research is applied in terms of purpose and based on a descriptive/explanatory-analytical method. The statistical population is experts and city managers in the city of Karaj. The analyses were conducted based on descriptive and inferential statistics using path analysis with SPSS software. Based on the results of the research, in institutional capacity, the effectiveness of the indicators of laws and regulations in explaining the city development strategy, readability and transparency of laws and regulations in explaining the city development strategy, and in social capacity, finding and creating common points in terms of society and culture, developing participation in solving problems, and trust in the implementers of development and renovation projects have the greatest impact on the process. Also, based on the path analysis, laws and regulations in explaining the city development strategy have the greatest impact with a coefficient of 0.76, followed by finding and creating common points in terms of society and culture, readability and transparency of laws in explaining the city development strategy, and developing participation in solving problems are in second, third, and fourth place with coefficients of 0.63, 0.53, and 0.37, respectively.