Recently, the importance of semantics on the WWW is widely recognized and a lot of semantic information (RDF, OWL etc.) is being built/published on the WWW. However, the lack of ontology mappings becomes a serious problem for the Semantic Web since it needs well defined relations to retrieve information correctly by inferring the meaning of information. One to one mapping is not an efficient method due to the nature of distributed environment. Therefore, it would be a considerable method to map the concepts by using a large-scale intermediate ontology. On the other hand, Wikipedia is a large-scale of concept network covering almost all concepts in the real world. In this paper, we propose an intermediate ontology construction method using Wikipedia Thesaurus, an association thesaurus extracted from Wikipedia. Since Wikipedia Thesaurus provides associated concepts without explicit relation type, we propose an approach of concept mapping using two sub methods; “name mapping” and “logic-based mapping”.