Introduction: Insecurity, potential threats and lack of security can lead to dissatisfaction and insecurity of the citizens of Greater Tehran. By participating, NGOs can provide services and sustainable security by supporting vulnerable groups. Accordingly, in the present study, the effect of Saman participation in promoting the security of Tehran metropolis was investigated. Method: The present study is applied in terms of purpose and method is descriptive-analytical. The data were collected as a combination of documentary and survey (field) studies; The statistical population includes: experts in the field of security and law enforcement; And the citizens of Tehran is large, using the multi-stage cluster sampling method and Morgan table, 1618 people were determined as the sample size. The data collection tool was a researcher-made questionnaire whose validity was confirmed using face validity and the reliability of the tool was confirmed by Cronbach's alpha. Also, the relationship between independent and dependent variables was investigated using multivariate regression analysis and regression test was used to evaluate the correlation between these two variables. Findings: According to the findings of this study, more than 60% of the respondents believe that the participation of Samnahs has a positive effect on improving the security of Tehran metropolis. Multivariate regression analysis also showed that there is a significant relationship between the participation of Samans and Tehran security. Also, this analysis showed that the participation of semen has the greatest impact (with a beta coefficient of 0. 561) on law enforcement security; And economic, political and socio-cultural security come next. Conclusion: Semans with any kind of orientation can play a role in expanding the security of Greater Tehran with two roles: "grounding (role of grounding)" or "executive activities (role of agent)".