Ontology construction is a hot topic in semantic research.This paper proposes constructing the domain ontology of political sensitive Information with Political Information as knowledge source data.By the using of ontology itself contains the description logic consistency reasoning verification mechanism, the constructed ontology library can be applied to multiple fields, such as performance evaluation, marking system, semantic network retrieval semantic proofreading and so on. It shows that the research and implementation of the construction of sensitive information ontology based on Protege and semantic reasoning has important practical significance and extensive application prospect. ① abroad, according to ontology construction method chanting time to sort are : IDEF4 method;