In this paper, the conceptual model for bibliographic information consistent and compatible with MARC is presented. The modeling requirements are derived from MARC-related models such as MARC21, MARCXML and MODES. To meet these requirements, this paper proposes the conceptual model based on MARC formalism. The model composed with aggregation relationships among bibliographic data elements can use semantic tags of XML. As the model can be realized into diverse structures, it will be effectively applied for the development of bibliographic information management systems. Since MARC defines only record format and has the limitations in semantic representation, the metadata system that can expand bibliographic data elements in MRAC into metadata level is strongly required.