The National Diet Library and OCLC (Online Computer Library Center, Inc.) agreed to provide internationally approximately 5 million bibliographic data created by the NDL via WorldCat, a bibliographic database operated and maintained by OCLC. Data to be provided are monographs and authorities of JAPAN/MARC.

OCLC is a non-profit library service organization whose purpose is to enhance worldwide bibliographic access by sharing catalogs which lead to reduction of library management costs and by sharing knowledge and information through library cooperation. More than 70 thousand libraries from more than 170 countries and regions are participating as of June 2010.

Registered users of the OCLC will be able to download bibliographic data of the NDL from WorldCat and edit them. Those who are not registered will be able to search these bibliographic data via WorldCat. The NDL will not conduct interlibrary loan via WorldCat.

JAPAN/MARC is scheduled to be accessible via WorldCAT in August 2010 at the earliest. Details will be announced on the NDL website.