Assembly is an important part in production and development of complex products. Flexible assembly retrieval is one of the key issues to find the reusable model. The main objective of this paper is to extend the model of ontology-based assembly design for model reuse. Firstly, we propose a representation of assembly structural data including topological structure, assembly semantics, and geometrical information. Secondly, we enrich assembly design (AsD) ontology for knowledge captured and shared in Web Ontology Language 2 Description Logic (OWL 2 DL) and Semantic Web Rule Language (SWRL). And then, we define the matching strategies and similarity assessment for two matched models. Finally, we illustrate the validity of assembly design representation for model reuse through experiments.