In this study, the present condition of 8 Open APIs for books, such as Naver, Daum, Aladdin, Amazon, Google, KERIS, LibraryThing, and OCLC, were compared and analyzed. In addition, the bibliographic records of 167 samples of visible ‘light & paraphotic’ (DDC 535) classifications were selected from the bibliographic records of the library of C university, and the effectiveness of the Open APIs were compared and analyzed. On the basis of the results of this analysis, 12 Open API application models, which were judged to be useful in expanding the function of the access point of the bibliographic records and enhancing the library catalog using Open API, were experimentally implemented. Various methods of augmenting access points of biblio- graphic records and expanded library catalogue were investigated using the unique identifier described in the KORMARC fields of 001, 010, 012, 020, 035, 246, 505, 520, 850, 856 for the integrated format for bibliographic data, and Open API. Finally, using Open API for the brief display and detailed display screen as a result of search of the OPAC of the sample bibliographic records, the devices for the expanding library catalog were implemented as examples.