Functional Requirements for Bibliographic Records (FRBR) is considered as a useful tool for improving the function of OPAC. Applying FRBR to OPAC is to emphasize collocation of MARC records used in OPAC. Thus it is meaningful to examine the characteristics of MARC format, in order to make clear the possibilities for FRBRization, which makes search capacities of OPAC more effective by extending collocation level. This paper describes, first of all states quo of catalogs and FRBR in general, as well as the concept of a Work in catalogs and FRBR. Then this examines the characteristics of Japan/MARC format in terms of FRBR. The result of the study showed J/M format has only a few element which contribute to Work. This means that J/M is weak in terms of access point comparing to MARC21. Finally, this concludes with the suggestions to improve J/M format by using uniform titles as an access point of title, more rigid authority control of access points, and then.