Semantic conflict is the conflict caused by using different ways in heterogeneous systems to express the sam eentity in reality. This prevents information integration from accomplishing semantic coherence. Since ontology helps to solve semantic problems, this area has become a hot topic in information integration, In this paper. we introduce semantic conflict into inform ation integration of heterogeneous applica-tions. We discuss the origins and categories of the conflict. and present an ontology based schema mapping approach to e-liminate senlantic Conflicts.