The purpose of this study is to review and analyze the overlapping functions and activities of the nationwide scientific and technical information network system This study is helpful for users to gather information and for librarians and nations to reduce wastage of budgets through discarding the duplicated expenses of performing activities of the network systems. The research targets are KISTI and KERIS, which are functioning as the information network systems in the fields of science and technology. The research methods are literary reviews for theory background and analysis of their activities from internet homepages. As a result of the research, it is found and confirmed that there are some overlapping and duplicating functions and activities in the network systems.