The current technological revolution pushes forward the innovation in the library information systems. This study proposes functional requirements and an architectural reference model of Semantic Library, recognized as a prototype of next-generation library information systems, that is a seamless convergence of the library information systems and the Internet technologies. Semantic Library can realize semantic interoperability and integration based on ontology and metadata, and also renovate information services for users with openness, sharing, participation and collaboration. Semantic Library will be effectively implemented by means of service-oriented architecture and the logical structure of FRBR. In this study, a reference model of Semantic Library consisting of 6 horizontal layers and 3 vertical elements is presented as a next-generation model of library information systems.