Abstract: On the basis of syntactic-semantic method of pattern recognition, and in association with expert tool network developing for expert systems, a type of semantic network is proposed in this paper. The basic element of the network is called COURSE. Each COURSE is described by an attributed context-free grammar. In order to describe the semantic network, the attributed grammars are expanded as follows: (1) The node labels as well as branch labels are realized as concepts which can be described by other concepts; (2)Contr01 strategies are introduced into an attributed grammar explicitly. Such semantic network not only can be applied to pattern description, but also can be applied to knowledge representation.