Throughout the IT communities, it has been acknowledged that ontology plays a key role in representation and reuse of knowledge. This paper discusses some issues of ontology construction for engineering data management, such as knowledge discovery, knowledge representation and semantic services. All discussions are followed by a running example of engineering data management. Based on the user needs with five phases of engineering design, the issue of knowledge discovery will be presented. The

more »

... uilt knowledge base contains basic knowledge models and vocabularies for knowledge integration. With the semantics of semistructured data, the hierarchical relations of concepts in engineering data have been extracted for reuse in future engineering design based on some clustering techniques of data mining. Semantic services for engineering design will be provided with the ontology-based schema.