Abstract:Ontology can formally describe concepts, terms and relationship of the special domain, but it can not express the fuzzy information. To solve the problem of the fuzzy information’s description in ontology, fuzzy description logic was employed in the construction of ontology. A 5 tuple fuzzy ontology model was established, including roles set, examples set, fuzzy assertion set and fuzzy relationship set. Based on Tableaus algorithm idea and case studies, the paper gives the solution method of the reasoning problem of fuzzy ontology. The correlation between key words was processed with the new NGD algorithm by means of Google search, and convert the results into membership degree of fuzzy ontology at last.