This study aims to perform an evaluation of directory services provided by major Korean search portals: Naver, Daum, Yahoo-Korea, and Empas. A directory service of Open Directory is also compared. These directory services are evaluated in terms of the coverage, category creation criteria, site selection criteria, breadth and depth of hierarchy, clarity and currency of category names, order of category listing, and overall classification system. The results of this study can be implemented for the development and improvement of portal's directory services. Users can refer to the results of this study in choosing directory services from search portals.