The main purpose of the Semantic Web expresses the information as intelligent forms, enables better computers and people to work in cooperation. Ontologies, as meaning providers, play a key role in this effort. Currently, the OWL Web Ontology Language is used as a description ontology language that is the main of technique for storing ontologies. On the other hand, traditional relational database systems are often used as best mechanisms for storing, querying, manipulating the information, and have some benefits such as transaction management, security. For this reason, there is a need for storing ontologies represented by OWL into relational databases is proposed. Therefore, principles of mapping OWL concepts to relational database schemas are presented with an implemented tool, which is the purpose of this paper.