Abstract: Based on the self-determination theory, this study proposes a structural equation modeling to research extrinsic incentives(trust, reciprocity and reward) which exert influences on IUR knowledge sharing. The study indicates that trust strengthens interpersonal relationship and enhance knowledge sharing. To achieve this, reciprocity and reward has to enhance self-efficacy. Interestingly, in the process of IUR knowledge sharing, this study finds that reward positively affects perceived autonomy to enhance knowledge sharing instead of alleviating it.