semantic internorabiliti bacame a critical issue today's information systems ontology-based opproach to solve samantic heterogeneity has been proposer by many researchers in this paper, we claim that contertual knowledge is crucial for users who intend to share and exchange their conceptual models eristing modeling languages are not capaple for defining such type of knowledge; we propose a well-defined meta-model to describe contertual knowledge implicitly hidden in conceptual models. the meta-model tries to close the formality gap by using ontologies as a backbone. the meta-model provides ontological primitives allowing us to interpret correctly inherent semantics of conceeptual models.