The aim of the present study was to investigate the relationship between ethical climate and organizational citizenship behavior with the mediating role of organizational justice among high school teachers in Tehran. included all teachers (382 people) of high school teachers in Tehran were selected by Multi-stage cluster sampling method. For data collection were used the three Questionnaire of Ethical Climate (Victor& Collen, 2006), Lee & Allen (2004 Organizational citizenship behavior, and organizational justice (Moorman and Niehoff, 2001). Data analysis was done by using structural equation modeling in AMOS And Spss-₂₂  software. The results showed that there is a positive and significant correlation (0.56) between the ethical atmosphere of the organization and the citizenship behavior of teachers. Organizational justice also has an influential role (0.25) in relation to the moral climate and organizational citizenship behavior of teachers. The more positive and meaningful the ethical climate in schools, the better organizational justice will be and the better and more effective citizenship behavior teachers will have. In general, it can be concluded that considering the direct and positive effect of ethical atmosphere on organizational citizenship behavior, it is necessary for school principals to take effective measures to create a favorable ethical atmosphere in schools to improve and enhance teachers' citizenship behavior.