Researchers have developed various types of Knowledge Management approaches that only focus on managing organizational knowledge. However, these designs are inadequate because employees are often needed to access knowledge from other knowledge sources in order to complete their works. Therefore, a new interorganizational Knowledge Management practice is required to enhance the sharing of knowledge across organizational boundaries in their business networks. In this paper, we investigate the application of ontology mediation that provides mechanisms of reconciling inter-organizational knowledge. An ontology-based Interorganizational knowledge Network that incorporates ontology mediation is developed so that heterogeneity of knowledge semantic in the ontologies could be reconciled. The reconciled inter-organizational knowledge could be reused to support organizational Knowledge Management process semi- or automatically.