Ontology development method is a method that shows how to construct an ontology. Many approaches have been reported for developing ontologies. Almost all of them are derived from traditional software development methods and consequently, have inherited their weaknesses. In the last decade, agile methods have appeared in software development area. These methods attempt to solve some problems of traditional methods. In this paper, one famous agile method that is known as Extreme Programming (XP) is adapted for ontology construction. Also, we report the ontology constructed using this method.