The MARC format has allowed for decades the description and exchange of bibliographic and cataloging institutions, promote access to informational content contained in various collections. However, with the exponential growth of information and document generation (especially digital), have demanded greater flexibility and interoperability between different information systems available. In this scenario, the XML markup language aims to facilitate and optimize the management, storage and transmission of content via Internet, currently embodied in various sectors and areas of knowledge for its ease of handling and operational flexibility. Given this, we carried out an exploratory study of theoretical analysis, identifying the appropriate format MARCXML in the construction of forms of descriptive representation for information resources in open files, metadata standard as a complex and flexible, which will enable interoperability between information systems heterogeneous, and their advantages and flexibility in the transfer of bibliographic and cataloging and access to information. As a result of this research, it is considered that the MARCXML is a format suitable for data describing a complex structure. It is concluded that the measure increases the complexity of the documents in the repositories and open archives, longer justified a metadata structure, such as MARCXML format, which supports the description of the specific informational resources, since this initiative and is not nor will it estringindo to scientific documents, but expanding to other types of information resources increasingly complex and specific, requiring also an apt description for the specific nature of bibliographic entities
