律令制是古代東亞世界的構成要素。目前在日本古代史研究中的律令制研究，是關注日、唐律令的差異，藉此發現了日本律令的獨特性，並得以看出日本古代天皇制的固有形態。筆者是從田租、調庸等租稅制度著手，指出了在宗教的性格和在地首長的支配下，古代日本如何整合其固有共同體的性格以建構日本律令制的形態。此雖一方面被視為日本的特色，然亦具有東直世界所共通的律令制之特色。因此筆者乃嘗試著思考：所謂古代國家的徵收租稅究竟是怎麼樣的情形。 日唐的律令制或有少許的不同，然做為稅制核心之課役制度，皆是向正丁課徵均額的人頭稅。但是漢代的算賦和北朝的租調制，均是以鄉和三長為徵稅單位，即以全體為基準，按其口數和戶數來稽徵，鄉的役人和三長負有徵稅的責任。在唐律中亦復如此，民眾個人是否繳稅並不是問題，地方官所申報的課口數的虛假才是問題所在。人頭稅與其說是由各正丁所納入，毋寧是濃烈地帶有以鄉和里為賦課基準之意義。實際的徵稅乃委託里正和鄉長等基層的官吏，掌握戶口數的公文為計帳，日唐都是戶數、口數等的統計帳簿。唐代是以里正為中心，由鄉、里所調製，日本則是由郡司來彙整。國家為稽查其戶口之正確與否而設有貌閱的制度。 人頭稅作為一種課役制的本質，在於以課口數決定徵稅額的粗糙支配方式，以及由地方官根據計帳的課口數來承攬課役的賈納的組織架構。然而對照於唐代的鄉、縣、州之各階段多層級地包攬一定戶口數的貢納，日本則是以郡做為承包納稅的單位，里和國均沒有被定位為負責貢納的單位，如是存在著和唐的差異性。

One important constituent of the East Asian World was the Law and Code System. By examining this system in Japan, we found its differences from the Tang Law and Code System, and identified its Japanese uniqueness which later contributed to the rise of the Emperorship. This essay tries to trace the operation of the rent and tax system in ancient times and its role in the making of distinctive Japanese law and code system. In Tang China, all the adult males were taxed evenly. The basic government unit in charging tax is Xiang district and San-zhang official during the Han, Northern Dynasties and Tang. The problem is the false report of the numbers of adult males by the local officials. In Japan, just as in Tang China, local administrations were responsible for the creation of tables and lists of the household and male statistics. In case of Tang China, that local administration was the Xiang district and Li village; whereas in Japan it was the County (jun)to be accounted for. Moreover, to avoid malpractice, in both countries there was a Mao-yue system to supervise the tax collecting. Unlike Tang China, the Li village and Guo district offices did not play a significant role in the Japanese Tax System. This is one of the differences between China and Japan.