Abstract: Constructing semantic overlay networks is an important way to support semanticsbased search and enhance search performance and scalability of the P2P networks. The existing P2P semantic overlay networks based on the taxonomy hierarchies can not fully utilize the semantic information contained in the taxonomy hierarchies. Therefore, a taxonomy hierarchy based P2P network (TBSN) is presented in this paper, which fully considers the characteristics of data sources employing taxonomy hierarchy to describe the contents of their objects. It dynamically clusters peers into deferent semantic clusters based on the semantic information contained in the taxonomy hierarchy, and organizes the semantic clusters into semantic routing overlays, thus forming a semanticsbased P2P network. Each semantic cluster consists of a superpeer node and more peer nodes, and only responsible for answering queries in its semantic subspace. A query is firstly routed to the appropriate semantic clusters by an efficient searching algorithm, and then forwarded to the specific peers that hold the relevant data objects; so the peers involved and messages to send are reduced and the network performance is greatly enhanced. Preliminary evaluation shows that TBSN achieves a competitive tradeoff between search performance and overheads, and load balance among clusters and data semantics within a cluster is all well maintained.