This study aims at identifying the factors affecting the promotion of social capital and its impact on reducing social alienation. The method adopted was combined and of nested type and collecting the quantitative and qualitative data (survey-cognitive phenomena) was done simultaneously. The quantitative data were collected through two questionnaires of social alienation and social capital from 410 students of Tehran University and Science and Research Branch of Islamic Azad University through proportional stratified sampling method. The qualitative data were collected through purposive sampling and semi-structured interviews with 16 people until the stage of theoretical saturation. The collected data were then analyzed through SPSS25 & Atlas ti software. The findings of the quantitative data analysis showed that the variable of social alienation has a significant and inverse relationship with those of empathy (0. 01)-0. 13 and trust (0. 001)-0. 21. Qualitative analysis of 19 categories including globalization, change in values and lifestyle, gender stereotypes, media, education, religious values, higher education, public spaces, social welfare, feelings of relative deprivation, social norms, family, social adequacy, network of mutual trust, good governance, meritocracy, crisis management, economic instability, and employment and business were extracted. Overall, the results showed that in order to promote social capital and reduce social harms, planners should take comprehensive attention to economic, cultural, political, and social areas into their serious consideration.