Abstract: [Full-text in Persian]. This research aimed to “explain the effect of the green supply chain management on the supplier’s function through the accumulation of social capital in logistics management and products of the National South Oil Company”. The research method is descriptive-analytic and correlational. This study was conducted in two phases: qualitative and quantitative. After extracting 5 main factors (green supply chain management, structural-social capital, and communicative-social capital, environmental and executive function) and 28 secondary factors in research, the survey found through the questionnaires. The population consists of the employees of the logistics management and products of the National South Oil Company (190) is formed by using Morgan and Krejcie and simple random sampling 116 were chosen. In order to measure the validity, convergent and content validity and for measuring the reliability of measurement instruments, Cronbach’s alpha was used. Data analysis was done through statistical software Smart PLS and SPSS. Results showed that all hypotheses were confirmed except social capital which is not effective in environmental-function. It was also demonstrated that social capital (relational and structural) plays a decisive role in the relationship between green supply chain management and function (environmental and executive). Therefore, it is necessary that studied companies in this research pay more attention to the explaining the role of social capital with the proper management and staff training.