Hon-keizu' is the second oldest extant family tree, following "Enchin Zokusho Keizu" (Family Tree of Enchin (Buddhist monk) as Layperson) (one of 'Records and Books concerning Chisho Daishi Enchin') (also known as 'Wake-uji Keizu' (Family Tree of the Wake Family)), which are also designated as national treasures.
「本系図」は、現存する日本の古系図としては、同じく国宝である『円珍俗姓系図』（「智証大師関係文書典籍」の1つで、「和気氏系図」とも呼ばれる）に次ぐものである。