With the Web evolving towards a Semantic Web, it is believed that the available information will be presented in a meaningful way to allow machines to automatically process its content. Besides the individual processing, a better information exchange among Web applications is desired. For this purpose, mechanisms are called for guarantee the semantic interoperability, that is, the identification and compatibility of information. In this direction, ontologies are used as one resource to make available a structured vocabulary, free of ambiguities. Ontologies provide a well-defined standard to structure the information and to promote formalism for automatic processing. In this work, we propose one strategy for ontology interoperability. The Ontology Taxonomic Alignment Component - CATO, which is the result of the implementation of this proposed strategy, provides an automatic taxonomic ontologies alignment. In this way, the alignment is obtained by a three-step process. The first step is the lexical comparison between the concepts from the entries ontologies. It uses a trimming mechanism of the related associated concepts as a stop condition. The second step is the structural comparison of the ontologies structures used to identify the similarities between common sub-trees. The third step refines the results of the previous step, classifying the similar identified concepts as very similar or little similar, according to a pre-defined similarity measurement.