Ontology is defined as a formal explicit specification of conceptualization , the network management knowledge model based on ontology is explored .The framework of knowledge model is presented , which is divided into primitive model and integrated model.Primitive model includes information models, function models and network

models .Integrated model is the result of integration of primitive models based on requirement of network management .The integration of knowledge model is based on ontology algebra and the process of knowledge model is based on ontology inference and query .A prototype of NMS is designed , which is based on the netw ork management knowledge model.The main characters of the prototype are separation of know ledge process and information process, customization of supported operations and know ledge level integrated network management .The validity of knowledge model is illustrated by the prototype.