Hypermedia enables users to perceive an abstract level of concepts more clearly and easily than a plain text by providing powerful and maneuverable system interfaces. It has been applied to various fields including design, documentation, information retrieval, manufacturing, education, and training. However, it lacks intelligence which is most critical for intelligent systems. Expert systems (ES) have been very successful in many domain areas. However, ES also has several problems including knowledge transfer (user interface) and knowledge acquisition. Among the problems knowledge transfer can be alleviated by using a hypermedia technology, since hypermedia allows more dynamic user control of the information in the knowledge base. ES also can alleviate the inherent problem of hypermedia since it has a reasoning ability. This paper discusses an integration of ES with hypermedia, which provides the mutual benefits of each system to remedy parts of the above mentioned problems. Two architectures of integrating the two systems are presented. The LOCUS system, a prototype, has been developed to test one of the proposed architectures in this research. The integration of ES with hypermedia enhances usability, interactivity, learning ability, flexibility, adaptability, intelligence of the system and can be used in various fields (e.g., CAD/CAM design, simulation, intelligent manufacturing, training, education, etc.), since it offers several amenities as described in this paper.