This paper introduces the needs of information interoperability on advanced network-based applications — Grid computing. The Grid has emerged as an important new field, distinguished from conventional distributed computing by its focus on large-scale resource sharing, innovative application, and, in some cases, high-performance orientation. The paper describes the concepts of Information-Flow Theory and using them to support information interoperability in the Grid. It presents the layered model for an agent-based information interoperability system. It shows that the integration of agent technology and ontology can improve the automatic process of information interoperability.