When the right of cadastral surveys was transferred to kokushi from the central government, the shoens and private lands (lands of local lords such as gunji (district managers), goji (a local government official under the ritsuryo system) and so on) without chiden (small scale land already developed by tato) or kugen (official documents authorized by kokushi or gunji (local magistrates) for transfer of the ownership of private property) were confiscated one after another into kokugaryo (territories governed by provincial government office) in order for them to secure tax revenue (it is clear that this authority was strong because when the shoen of sekkan-ke in Wakasa Province was confiscated by kokushi and it was pointed out that FUJIWARA no Yorimichi, the chief adviser to the emperor, was wrong in kugen, the judgment of kokushi was justified (in the description on September 1 and 13, 1025 in "Shoyuki" (Diary of FUJIWARA no Sanesuke)).
国司は中央政府から検田権を委譲されると、治田（ちでん、田堵の開発した小規模の墾田）や公験（くげん、正式に土地所有を認めた文書）のない荘園・私領（郡司・郷司など在地領主の所領）を次々に没収して国衙領に組み入れ、税収を確保しようとした（この権限が強かったことは、若狭国にあった摂関家の荘園が国司に接収された際に関白藤原頼通が国司に公験不備を指摘されると、国司の判断を妥当とした（『小右記』万寿2年9月1日・13日条）ことでも明らかである）。