Abstract: Ontologies need to evolve continually,for the application environment and users’ application requirements are always changing.The most important issue in the ontology evolution is how to establish the right relation between the newly arising information and the existing knowledge in the ontolgoy.An ontology evolution framework based on background knowledge is introduced,which can exploit the relation between the newly arising information and the existing knowledge in the ontolgoy,and improve the the ontology evolution process.

Key words: ontology, ontology evolution, background knowledge