This work is part of prototype Semantic Integration Tool for Spatial Data). Our aplication is able to assess similarities and the differences between clases in one ontology. This tool take classes from XMI models and spatial features are obtained from SIT-SD ontology (combination of WordNet and SDTS) and by means of a semantic match process, we assess the similarities and differences between classses. Semantic similarity play an important role in both retrieval and integration information by enable identification and treatment of similars, so it is posible development technics for integrating; covering needs of federaded users, we believe that is one step towards interoperability between Geographic Information System.