Abstract: The UML class diagram retrieval based on semantics and structure was proposed under the background of software reuse. The reuse model of UML class diagram was constructed and the reuse repository structure of UML class diagram was defined. The conceptual semantic distance of ontology was applied to the semantic similarity measure of UML class diagram and a graph was used to represent the structure of UML class diagram for the structural similarity measure. The retrieval requirements were formalized based on the retrieval procedure and the retrieval algorithm of UML class diagram was proposed. The proposed algorithm was validated from three retrieval types(semantics， structure and hybrids) according to the proposed criteria. The experimental results showed that the proposed algorithm is superior to other methods in terms of both retrieval quality and efficiency.

Key words: UML class diagram, semantics, structure, similarity measure, retrieval