opened in Yamaguchi, Yamaguchi Prefecture, Japan, in 1959 as the country's first dedicated modern archival institution.
In Shà Âwa 27 (1952), the Mà Âri family, former daimyà  of Chà Âshà « Domain, deposited its domainal documents with Yamaguchi Prefecture, whereupon they were stored, alongside materials gathered by the pre-war Prefectural History Compilation Office, at . These items were transferred in with the opening of Yamaguchi Prefectural Archives in 1959; donations and deposits - including materials from the Tokuyama Domain Mà Âri family - have continued since.
The archives holds approximately 530,000 documents, roughly divided into five groups:
The holdings include seven Important Cultural Properties, two Prefectural Cultural Properties, and three Municipal Tangible Cultural Properties.