This thesis presents a multi-agent framework for industrial information management, condition monitoring and real-time control. Power systems are distributed, complex systems. Various utilities and computational devices form a modern substation, where these devices collect and make available a large quantity of information. Measurement data, concurrently triggered by events, maintenance records and documents are stored in either logical or geographical distributed locations, which make it difficult to retrieve and make use of a piece of interesting information for a particular purpose. The objective of this thesis is to describe the development of a framework to manage concurrent distributed information. The framework provides an "intelligent" means to deal with concurrent information. Furthermore, knowledge representation and cooperated control methodologies are introduced, as well as the capability for seamless integration with existing information systems. The framework, proposed in this thesis, is based on the concepts of multiagent systems and ontology. A multi-agent system mimics a human society to achieve goals through agents' cooperation and negotiation. Ontology, the cornerstone of the cooperation and negotiation, is the common knowledge context representation, that provides a semantic ground for each individual agent. Therefore, an ontology for annotation of the power system and an ontologydriven information-querying interface are illustrated in detail, followed by the description of the proposed framework. In this framework, software agents derived from various agent roles are used to represent data sources and functions. FIPA Agent Communication Languages (ACL) and protocols were used for agent communication. The framework provides a feasible solution to extending the information services of conventional Supervisory Control and Data Acquisition Systems (SCADA) by adding and removing agents services, without a significant affect on the other system activities and agent organisation. This thesis also describes a prototype implementation of the framework—a substation information management system. The prototype system demonstrates some functionalities such as information query, management and cooperated control of a relay. Various agents have been invoked to provide these functions, for example, the personal assistant agent, the Information Management Unit agent, and the ontology agent. Details of the implementation of these agents are presented. Two applications have been carried out to further evaluate the feasibility and the flexibility of adopting this framework in a power system. A predictive transformer maintenance scheme was used to investigate the capability of integration and the utilisation of existing algorithms and methodologies. The relaying control application demonstrated the performance of agent cooperated control.