Power Grid reasoning expert system is a complex system. To solve knowledge sharing of knowledge Base in expert system, we abstract and analyze the power grid security investigation procedure by using ontology Technology. With ontology-based Power Grid knowledge base, we establish associated relationship of procedure vocabularies. In this paper, we introduce and analyze of semantic reasoning tools such as Jena. The reasoner mechanism and inference rules of grammar has been included and explained. At last we give a specific application of security investigation procedure ontology and reasoning.