摘要： 20世纪以来行政法发生了两个重大转变，即从面向司法到同时面向行政的行政法和从面向外部的行政法到同时面向内部的行政法。内部行政法是行政机关对外行使权力的一个支撑体系。作为担保行政行为合法性的内部行政法，与外部行政法一样都是“控权法”。内部行政法担保结构的制度基础是由三大行政法律关系构成，即行政机关—行政机构、行政机关—行政机关和行政机关—行政机关工作人员。内部行政法担保结构的类型构造分为内部行为法效果内化和外化。内部行政法实现担保行政行为合法性的方式主要有不利决定、科以义务和控制措施。

关键词: 内部行政法, 外部行政法, 内部行为, 行政行为合法性

Abstract: Since the 20th century，there have been two major changes in the administrative law-from the judicial-oriented to the administrative-oriented，from the administrative law that faces the exterior to the administrative law that also faces the interior.Internal administrative law is a supporting system for the executive authorities to exercise their powers.Internal administrative law，which guarantees the legality of administrative acts，is the same as the external administrative law，which aims at controlling power.The institutional basis of the internal administrative law guarantee structure is constituted by three major administrative legal relationships，namely，the administrative organs-administrative agencies，administrative organs-administrative organs and administrative organs-staff members of administrative organs.The type structure of the internal administrative law guarantee structure is divided into internalization and externalization of the internal act law effect.The ways in which internal administrative law guarantees the legality of administrative acts mainly include unfavorable decisions，obligations and control measures.

Key words: Internal Administrative Law, External Administrative Law, Internal Act, the Legality of Administrative Act