Built on the semantic network based hypermedia model, a hypermedia retrieval model based on pattern matching is proposed in this paper by introducing the concepts of database schema, model constraint graph and stratified schema dependency graph. Furthermore the formal definition of graph algebra is given out, which guaranteed the model抯 retrieval ability. On the one hand, this model can decrease the users?cognitive overhead. On the other hand, it guarantees the expressive capability of the retrieval.