In this study, the experiment was made to transform the relationship among terms in a thesaurus to ontology language as search tools for multilingual text. As a result, the equivalent relationship in the thesaurus can be expressed by different ways in the ontology, such as equivalentClass, equivalentProperty, sameAS, and so on. On the other hand, the associative relationship can be represented by ObjectProperty, DatatypeProperty, and inverseOf. For this test, first of all, the descriptors assigned by AAT and the descriptors from bilingual thesaurus by ICCD were translated into Korean. Then, the facet was used for conceptual equivalence among terms from different languages. The result of the study showed that using rdf:Property in ontology was the most effective way of transforming multilingual thesaurus into ontology.