Since the monjo created by the Sutra copying office during the 8th century (for about 50 years from the Jinki to Hoki era, [724 - 781]) were placed and have been preserved in Shosoin, valuable historical materials including koseki and shozeicho (balance sheets of tax rice) created in the Nara Period still remain today.
8世紀（神亀～宝亀年間の約50年）の写経所文書が正倉院に納められ、保存されてきたため、奈良時代の戸籍・正税帳などの貴重な史料が今日まで残ることになった。