MD4:integrated approach of determining semantic similarity among entity between different ontologies HUANG Hong-bin, ZHANG Wei-ming, DENG Su, DONG Fa-hua (College of Information System & Management, National University of Defense & Technology, Changsha 410073, China) Abstract:Oriented the demand of sharing information and service in the distribute network, this paper designed the metadata model based ontology. The MD3 model systematically evaluated semantic similarity across different ontologies dispense with integrating different ontologies into a shared ontology. Based on the MD3 model, focused on the not-hierarchical relations evaluating of concepts from different ontologies, extended the MD3 model to MD4 model to make the semantic similarity of concepts from different ontologies more comprehensive and precise. Key words:metadata model; ontology; semantic similarity; MD4 model