This study compares and analyzes the classes in the major special areas in the sociology, called "branch sociology" included in the Korean Decimal Classification 4th edition and Dewey Decimal Classification 21st edition. Especially it analyzes the related classes of specified areas(branch sociology) of sociology including those of arts and sports, sciences, languages, society, region, etc. class by class. In this analysis two systems show many differences in the classes included and in the locations of same classes. This analysis can be useful for the future revision of KDC.
