Background and objectives: Law enforcement is a dynamic and social organization and its most important task is to maintain order and security and to provide public and individual well-being in the community. Being aware of the status of social capital is one of the requirements for planning long-term development prospects as well as organizational planning. Accordingly, the importance of investigating the effectiveness of police social actions in increasing the social capital of the Qazvin Police Command seems very clear. Methodology: This study is of an applied research type which has been conducted in survey method. The population of the study was all the residents of Qazvin (sample size 480) who were selected by stratified random sampling method. The method of data collection was field study and questionnaire was used for data collection. For the analysis, we used exploratory factor analysis, KMO coefficient, Bartlett and Friedman test. Findings: The value of KMO index on the impact of law enforcement's social measures on social trust, social participation, commitment to social security, and attempted crime prevention were 0. 82, 0. 821, 0. 806, and 0. 820, respectively. Results: The results show that social actions, the presence of staff members alongside people in different religious ceremonies, the implementation of multiple programs for Police Force Week, the implementation of cultural programs on different occasions, face-to-face training classes and training and information dissemination through the installation of banners are the most effective in the social capital of citizens.