It is necessary to find a genre classification by reflecting the needs of users since a subject that makes up the highest proportion of books in the school library is fictions in literature and KDC cannot accept user's need to access fiction in school libraries. This study suggested the genre classification for fictions in school libraries through surveying classification of fictions in domestic and foreign libraries, and comparing between classification systems of online/offline bookstores, KDC and DDC. For developing the genre classification system, it is to collect genre terms for fictions, to extract 14 genre headings among them, and to assign the acronym of English genre terms as classification notation. For applying the newly developed genre classification, KDC number of one middle school library was converted as the 3 methods such as combination of KDC, genre term before 800 and only genre terms. This study could contribute to suggest the genre classification of fiction to reflect user needs and to overcome the limitation of hierachical classification in KDC.