The predecessor of CNKI, China Academic Journals CD-ROM (CAJ-CD), was launched in January 1997 as China's first academic journal search system that publishes regularly. It included 3,500 Chinese journals in the fields of sciences, engineering, humanities, and social science. Published by a unit under
Tsinghua University and created with the permission of the
National Press and Publication Administration, the database was released as
CD-ROMs, with each containing journals of a field. A disc was released monthly, except the volume on
the arts, history, and philosophy, which was released every two months. In 1999, the database could also be accessed on the web. In August 1997, the China Academic Journals Electronic Publishing House (CAJEPH) was established under the governance of the National Press and Publication Administration. The operation was run by Tsinghua University. CNKI owns a system called "China Integrated Knowledge Resources System," including journals, doctoral dissertations, masters' theses, proceedings, newspapers, yearbooks, statistical yearbooks, e-books, patents and standards. In 2013, CNKI became the second
DOI registration agency in mainland China, after the Institute of Scientific and Technical Information of China under the Ministry of Science and Technology. == Government investigations ==