When these miyake developed and expanded to a certain size, they became the bases of kohori (written as 県 in Chinese characters), which was a unit that the central government directly administered and controlled in local areas, and it is believed that they later developed into the kohori (written as 郡) of the ritsuryo system (a system of centralized government based on the ritsuryo code).
この屯倉がある程度発達・広域展開した段階で、屯倉を拠点として、直接的に地方を把握・管轄した単位が県（コホリ）であり、のちに律令制における郡（コホリ）へと発展していったと考えられている。