开、天年间度支司职权变化是唐代前后期财政机构转变的核心问题。本文指出度支司以开元年间脱离金、仓部进而集计划与执行于一身为基础,在天宝年间演变成为带有兼使、侵夺司农、太府等寺监职权的独步天下的财政机构,开、天时度支司的特征为唐后期度支使所继承。同时也论述了促使度支司变化的开元天宝政局。 The changes in the powers and functions of branch offices during the past and present periods were the core issues in the transformation of the financial institutions before and after the Tang Dynasty. This paper points out that in the first year of the Qing dynasty, the degree branch was evolved into a monopolized financial institution with concurrent powers of taking over, seizing the power of the Secretary of Agriculture, Tai Fu and other prefectures based on the plan and execution of the first year of separation from gold and warehouses, Open, the branch of the characteristics of the degree of support for the post-Tang inheritance. At the same time, it also discusses the Kaiyuan Tianbao political situation that will change the degree branch.