The purpose of this study is to identify users behavioral characteristics for using the online catalog opened in May 1996 at Duksung Women's University Library. 278 student users were surveyed from October 4th to 8th in 1996. Major findings are as follows. 1. Most users$(87.4\%)$ prefer the online catalog to the card catalog and regard the online catalog easy to use$(89.6\%)$ 2. $(65.8\%)$ of users are active users who frequently use the online catalog at least 10 times or more per semester. 3. $10.4\%$ of users feel the online catalog difficult because they do not know how to use it. 4. Most users prefer the menu search mode among menu, command and fill-in-blank search modes offered by DISCOVER. The most preferred access points are the title for known-item search and subject headings for subject search. 5. User's attitude toward the online catalog is very favorable$(83.5\%)$, however, the search success rate is rather low $(77.0\%)$ compared to that of the card catalog $(87.0\%)$ 6. The title and author are regarded easy to use among access points offered by DISCOVER. Classification numbers and call numbers are the least easy access points to use. 7. Since users show lack of knowledge of how to use the online catalog, education and training programs on the online catalog use for users are needed. 8. Users showed different search patterns for pursuing different search goals. The most preferred access points are the title for known-item search and subject headings for subject search. These search behaviors are different from those in using the card for both the known-item search and subject search was the title.