Information integration of heterogeneous digital parts libraries or electronic pars catalogs is one of issues in B2B procurements. We need to provide an integrated view for multiple information sources. Utilization of ontologies as the metadata descriptions of the information sources can provide an integrated view. However, in order to integrate independently developed ontologies, the mismatches among them should be resolved. In this paper, we propose an ontology of meta-concepts, i.e. meta-ontology. The meta-concepts play the role of vocabulary to describe the parts library ontologies and provide well-established ontological semantics that helps the ontology modelers to consistently identify parts library concepts and systematically structure them. Consequently, the meta-ontology reduces the differences in the way the parts knowledge is interpreted and ensures the mismatches are confined to manageable mis matches, so that a software program can merge automatically. Modeling ontologies of mold and die parts libraries for B2B e-commerce is taken as an example to show how to use the meta-ontology. We also discuss how a parts library mediation system can automatically merge the well-structured parts library ontologies.