To share information on specific domain, the information systems define their own metadata and use it. But metadata mismatch problem must be occurred when we try to share the information among heterogeneous domains. This paper proposes the method for enhancing semantic interoperability among information systems in heterogeneous domain. For this, we define a concept model on metadata which is described in Metadata Registry (MDR) and design a method for semantic similarity measurement among instances of concept model. With this method, it will be able to select the optimum metadata for in-formation sharing of systems on difference-domains.