The Ouki records the golden age of FUJIWARA no Michinaga and Yorimichi and goes into great detail about its society, government, Court ceremonies and ancient practices, and considering that it is largely thanks to this diary that we know what we do about these aspects of life during this period, it is a historical record of immense value and importance.
藤原道長・藤原頼通の全盛時代の社会や政治、宮廷の儀式、故実などを詳細に記録してあり、それらを知るうえで大変重要な史料である。