The publish/subscribe model has become a prevalent paradigm for building distributed notification services by decoupling the publishers and the subscribers from each other. The semantics-based publish/subscribe system allows highly expressive descriptions of subscriptions and publications and thus is more appropriate for content dissemination when a finer level of granularity is necessary. In this paper we have designed and implemented a semantic-based publish/subscribe system that can be adapted into social networks where thousands of people can share their common interests through publications and subscriptions. We have described our ontology, defined publishers’ and subscribers’ data semantics or schema, provided a matching algorithm, portrayed the implementation and shown the result of an implemented publish/subscribe system that allows the users to publish and subscribe different kinds of news in a social network platform. Our experience shows that the semantic-based publish/subscribe system can enhance the current social networks by providing an effective content dissemination mechanism.