The higher-degree relation widely exits in the real world but is not being supported by the current Semantic Web. It needs to be converted into multiple binary relationships in the Semantic Web. However, the semantics of a higher-degree relation is not always the same as those of multiple binary relationships. Even if a higher-degree relation can be represented by multiple binary relations, the former often provides a more "natural" representation of the real world. Wand and Weber introduced the Ontology defined by Bunge into information modeling that is referred to as BWW ontologies. By using a mutual attribute rather than multiple binary relations to represent a higher-degree relation directly, BWW ontologies avoid the problem of inappropriate presentation of higher-degree relations. This paper presents an XML Schema for BWW ontologies to support the Semantic Web