The purpose of this study is to identify the relationship between the employees' perception of organizational justice and their prosocial behaviors, focusing on the moderating effect of employees' individualism and collectivism. The survey has been conducted for 200 participants working in Korean companies. The results show that the perception of organizational justice is positively related with their prosocial behaviors. Also, employees' individualism and collectivism is significantly related with their prosocial behaviors. Specifically, individuals who are more collectivistic or less individualistic performed more prosocial behaviors than those who are less collectivistic or more individualistic. Finally, employees' individualism/collectivism has moderated the relationship between the perception of organizational justice and prosocial behaviors. When employees have strong sense of collectivism, they performed prosocial behaviors consistently regardless of the perception of organizational justice. That is, even though they perceive organizational justice as low, they perform prosocial behaviors in some degree. However, when employees have strong sense of individualism, their prosocial behaviors have been significantly determined by the perception of organizational justice. That is, when they perceive organizational justice as low, they rarely performed prosocial behaviors. But, as they perceive more organizational justice, their prosocial behaviors have been dramatically increased. The implication of those results and future research questions have been discussed.