Ontology is increasingly seen as a key factor of semantic web. It makes information on the web more readily accessed and processed by applications. Ontologies mapping is required for combining independent and heterogeneous ontologies, which implements the interoperability across semantic web applications. This paper presents a new approach for ontologies mapping. We introduce the inference techniques of description logic, and transform the ontologies mapping from the computing of linguistic or structural similarities to the logical reasoning between concepts of different ontologies, implementing the semantic mapping of ontologies. Experiments show our approach outperforms the CTXMATCH algorithm in recall and precision when the rich relations exist between concepts of ontologies.