The achievement of some business goals requires more than individual capabilities and knowledge. Hence, it is necessary for different organisations to work together in order to achieve the goals. In this paper, an innovative agentbased architecture is developed to model ontology mapping and integration in a distributed and dynamic business environment where interactions among organisations may take place at unpredictable times, for unpredictable reasons, and between unpredictable organisations. Functionalities and implementation of involved agents are discussed. In addition, a three-layer user ontologies are introduced. Finally, demonstrations of ontology mapping and integration are presented.