The purpose of this study is to suggest EAD mandatory elements to share finding aids among the Archival Institutions of Korea. Three foreign EAD best practices for case studies: the EAD Best Practice at the Library of Congress(2008), the RLG Best Practice Guidelines for Encoded Archival Description(2002), and the OAC Best Practice Guidelines for Encoded Archival Description (2005) were analyzed. In addition, the Archival Description Rules(2008) as the data content standard of Korea and the descriptive elements which are were being used at Archival Institutions of Korea were analyzed. Based upon the results of comparisons among EAD elements, in-depth interviews were performed to investigate which EAD elements should be included in finding aids as a matter of exchange format. Based upon the literature review, case studies, and interviews, the rules and EAD elements for the archival institutions in Korea were designed and suggested.