This research aims to find out the effect of syntax on interoperability among metadata standards. The interoperability of “MARC21 in XML (MARCXML)”, “Metadata Encoding and Transmission Standard (METS)”, “Metadata Object Description Schema (MODS)”, “Metadata Authority Description Schema (MADS)”, “Dublin Core Metadata Initiative (DCMI)”, “PREservation Metadata: Implementation Strategy (PREMIS)”, “Technical Metadata for Text (TextMD)”, and “Metadata for Images in XML (MIX)” are examined. The first section of the paper describes the tools and types of interoperability among metadata standards. In the second section, METS is selected as a core standard. Finally, models of how the studied metadata standards interact with each other and with METS, based on an analytical-systematic approach, are investigated, and some patterns adapted with each model are planned. The results show that the use of appropriate syntax plays a key role in interoperating metadata standards, and leads to information system integration.