This study aimed to construct the Library Map Information System(LMIS) based on the Wiki theory of Web 2.0. We built this system because there was no collective source of information about every library in the world. Also, this system was developed to provide a library location information service by mashing-up with the Google Map. Through this study, the metadata applied to the newly constructed system was developed by using the Delphi method. A total of 13 experts including librarians of schools, public, academic, special, and national libraries as well as LIS faculty members and researchers, were commissioned as Delphi experts. Through three rounds of a Delphi survey analysis, the addition, modification, and deletion of the initial metadata elements was accomplished, and then the library contact/location information, library information, collection information, and event information was proposed. The metadata for LMIS was organized into four sectors and then 49 elements, each assigned to a sector.