Knowledge Management is the most important issue in the operation of an organization and it has been widely applied in various types of organization. The essential factor to ensure successful Knowledge Management is knowledge sharing. Knowledge sharing is defined in different ways, in general it means the delivery of knowledge (tacit and explicit), and most studies on knowledge sharing focus on “How to motivate subordinates of an organization to share knowledge with others”. However, relatively few has been on the organization justice that affects the behavior and attitude of subordinates. Organizational justice can be theoretically considered as an important factor of knowledge sharing. According to the social exchange theory, subordinates who recognize organizational justice tend to exhibit cooperative behavior as a reward. In the respect that knowledge sharing is a kind of cooperative behavior for coworkers, the employees who recognize organizational justice is likely to share knowledge in more effective manners. However, the theory set a limitation for us to explain how subordinates who recognize justice from organization or supervisors share their knowledge to coworkers. So we adopted justice heuristic theory to explain the limitation. According to the justice heuristic theory, knowledge sharing is a social dilemma arising in an organization and being decreased by trust. The theory also says that recognition of organizational justice works as a proxy for trust. Therefore organizational justice as the antecedent to promote knowledge sharing has an important meaning when knowledge sharing is observed from the viewpoint of social dilemma. The purpose of this research is to examine the relationships between organizational justice and knowledge sharing based on this theoretical background. Generally, organization justice was studied in terms of distribution, procedures, and interaction (interpersonal and information). Thus, the first goal of this research is to reveal the relationship between distributional, procedural,and interactional justice (interpersonal justice, informational justice) and knowledge sharing. The second goal is to study the moderating effect of interactional justice (interpersonal justice,informational justice) in the relationships between distributional, procedural justice and knowledge sharing. Therefore we hypothesize: H 1: There is positive relationship between distributional justice and knowledge sharing. H 2: There is positive relationship between procedural justice and knowledge sharing. H 3: There is positive relationship between interactional justice (a: interpersonal justice, b:informational justice) and knowledge sharing. H 4: The interactional justice (a: interpersonal justice, b: informational justice) moderates the positive relationship between distributional justice and knowledge sharing such that the relationship will be stronger when the interactional justice (a: interpersonal justice, b: informational justice) is high than interactional justice (a: interpersonal justice, b: informational justice) is low. H 5: The interactional justice (a: interpersonal justice, b: informational justice) moderates the positive relationship between procedural justice and knowledge sharing such that the relationship will be stronger when the interactional justice (a: interpersonal justice, b: informational justice) is high than interactional justice (a: interpersonal justice, b: informational justice) is low. Data was collected by giving questionnaire to 435 pairs of a supervisor and his/her immediate employee. 360 questionnaires were collected. Among those, 322 dyadic data were used for analysis. The results indicated that distributional justice and interpersonal justice were significantly and positively related to knowledge sharing, but procedural justice and informational justice was not. Besides, there was a significant interaction effect of interactional justice (interpersonal justice, informational justice) in the only relationship between distributional justice and knowledge sharing. In sum, Hypotheses 1, 3a, and 4a, 4b were supported. This research has theoretical and practical implications. First, in explaining relationships between organizational justice and knowledge sharing, this research viewed knowledge sharing as a phenomenon of social dilemma and theoretically refined relationships between organizational justice and knowledge sharing from the perspective of justice heuristic theory. And second, by demonstrating that the moderating effect of interactional justice( interpersonal justice,informational justice) in the relationships between distributional justice and knowledge sharing,it is possible to observe how important fair treatment from their supervisor is in knowledge sharing.