Social impact assessment (SIA) is one of the newest subjects in development-related issues, which has been started with USA’s environmental national policy. This issue has attracted immense attention in last five decade (from mid 70s) through the published results in related books and articles. Social impact assessment reflects the social results of interaction between development and society, while emphasizes the necessity of evaluating the post-decision impact by urban managers before taking action. This also provides an opportunity to the people, who are influenced by this intervention, to achieve the chance to participate in designing their future environment. So, estimating social consequences can be helpful in addressing concerns of social development in designing projects. The purpose of this paper is to evaluate the social consequences of constructing a Children's Park “Zafar Golchin” in district 10 of Tehran municipality. This paper is written to satisfy the policy of Tehran’s municipality, which is responsible for most of the urban projects, to consider the environmental, social and cultural consequences of the projects. In this evaluation, the method of research according to the goal is social impact assessment, and according to nature is descriptive-analytical, which studies the characteristics and traits of individuals. Also, in this paper the state of statistical society in the form of some attributes and variables after development interventions have been studied. According to the features in a park (sliding and skating), frequently usage of park by children in the surrounding complexes is one of the main functions of the Children's Park. Because of the playground in the park, mostly the children in the range of 10-15 ages use the park. So, one can claim that the most important social consequence of construction of Zafar’s Children park is positive effects of Park on kids (providing opportunities for playing, exercising, learning, reducing obesity and improving mental health). So, the kids are the most important community who are affected by the direct and positive effects of the park. Since, formerly the place of the park was a ruined place, where the surrounding residents were putting their garbage, it caused very bad odor in the area, and as a result, the second important effect of the park is its environmental effects in the area. Although, by accurate planning, the kid’s park can be a place for improving human merits, but by inaccurate and simplistic planning, it can be converted to a place which crimes will happen, and so it will have negative social, cultural and sociological on the residents. Some of the negative consequences which residents worry about are that the park will be converted to a place of accumulation of drug addicts and gangsters it will be a place for trading drugs, and formation of some illegal friendship.