Reviewing the outcomes of studies on contemporary information science during some periods and identifying the research area exposed in its studies are essential processes to develop the research and theories of information science and to establish the academic identity of information science. This study seeks to provide the some useful methodological approaches for establishing the research area of information science. The methodological approaches to research area of information science are as follows : (1) normative approach by concepts, definitions, and principles of information science, (2) content analysis of text books, (3) content analysis of curricula of graduate courses, (4) content analysis of graduate disserations or treatises, (5) IIS(Institute of Information Scientists)'s criteria for information science, (6) professors' need assessment, (7) interdisciplinary approach, etc. These are the representative types of methodological approach and have an enough validity and effectiveness in their own way. Therefore I think of that those should be integrately applied to establishing the academic identity of information science.