The purpose of this study is to analyze the structural model of classification, to compare enumerative schemes with faceted schemes and finding the facted schems used in the Dewey Decimal Classification. The Structural model of classifications can be divided to enumerrative schemes and facted schemes(analytico-synthetic schemes). Enumerative schemes represent the various kind of subject in different ways and have to not only list all existing combinations of subjects but also any of potential subjects. Faceted schemes is the decomposition of concepts into all possible characteristics which are known as facets. DDC was originally created as enumerative, but over 20 editions has moved increasing towards synthetic features such as the add instructions, and the seven auxiliary tables. Many DDC class numbers found in the Schedules may be subdivied by another number(or part of it) that has been drawn from the Schedules or auxiliary tables. This process of subdividing class numbers is called number building and it can be done only when there are number building instruction in the Schedules or Tables.