Abstract. In this paper we propose a social bookmark system using sev-eral metadata and personal network to construct a community-based on-tology. Our system allows users to browse friends ’ bookmarks on his/her personal network. The user can map their own tags onto more than one tag from different friends so that they are linked to the user. The matchmaker-based recommendation and network expansion method will work efficiently because it is derived from personal interest and trust. We also design an RDF-based metadata framework to support the open and distributed model.