The three key parts of citation index are the Citation Index, the Source Index and the Permuterm Subject Index. To identify the core elements for citation index database system, it analyzed the items that have been cited in references and source items of Journal of the Korean Society for Information Management from vol. 1 no. l(1984) to vol. 15 no. 3(1998). Ten core elements were identified and the description format was specified respectively. The core elements are author, organization that the author is affiliated, title of article, title or journal, volume/numberlpage numbers, year of publication, keyword, language, subject category, statistics of references in article. Also, characteristics of errors in reference citations were analyzed and categorized in the viewpoint of the citation index development of academic journals in Korea.