Taking the knowledge-intensive characteristics of governmental processes into account, an approach to analyzing, extracting and modeling e-government ontology by using both the IDEF5 ontology capture method and the web ontology language （OWL）, is presented. First, both knowledge-intensive activities and knowledge items can be identified by the analysis of governmental processes. Secondly, the IDEF5 ontology capture method is utilized to extract concepts, terms and statements from these knowledge items, which act as a starting point for ontology refinement and validation. To describe precisely the semantics of the ontologies, the OWL language is employed in our project to formally model these e-government ontologies with the help of Prot6ge-OWL tools. Finally, a case study about applying for social security cards （SSCs） in Shanghai local government is illustrated to demonstrate the effectiveness of the presented approach.
