本文係討德國法制中有關把國際法引入國內法領域之機制。條約因立法機關制定之條約法而引入國內法。條約位階等同於法律。立法機關得在條約法中授權行政機關對於特定之條約以命令引入國內法。此命令屬法規命令性質。習慣法由德國基本法第二十五條引入國內法。習慣法位階低於憲法但高於法律。引入國內法領域之國際法是否仍保持其國際法性質或已轉變為國內法，有二派不同見解:變質說與適用說。

This research focuses on the problem of the incorporation of international law into the German Law. International treaty is incorporated into German Law by statute passed by the legislative organ. However, the legislative organ can authorized the excutive organ to incorporate international treaty into municipal law lay making administrative order. International custom is incorporated into the German Law by Article 25 of the Constitutional Law. The hierarchical rank of the incorporated international law in the German Law sphere varies, depending on the rank of the norm which incorporates it. There are two different theories about the nature of the incorporated international law: transformation theory and adoption theory.