This study aimed to investigate the relationship between employees' perception of organizational justice and social capital in The National Tax Administration in the south of Tehran province. This is an applied study in terms of purpose, descriptive in terms of nature, and survey in terms of method. The statistical population included all employees of the National Tax Administration in the south of Tehran province. According to Morgan and Krejcie's table (1990), 214 people were selected as the sample size in simple random sampling method. Talebzadeh Organizational Justice Questionnaire (2011) and Kennedy Social Capital Questionnaire were used to collecting data. The research hypotheses were examined to analyze the data using the Pearson correlation coefficient test. The study results showed a positive and significant relationship between employees' perception of distributive justice, procedural justice, interactional justice, information justice, and the total score of organizational justice with the social capital.