For the heterogeneity problem among ontologies,this paper presented an algorithm based on sub-graph approximate isomorphic here. It was an extension of existing methods in ontology matching. Under the comprehensive application of features such as edit distance and hierarchical relations,it calculated the similarity of graph structures between two ontologies. Lastly, it determined the ontology matching on the condition of sub-graph approximate isomorphism based on the alternately mapping of nodes and arcs in...