This Article examines a structure of two Conventions of Space Station, compares 1988 Convention and 1998 Convention, and tries to apply "model" to it. The structure of 1988 Convention shows us three phases: the Convention as a framework, the bilateral memorandum of understanding and the legislation by domestic process of United States. There were many advantageous provisions for United States. In 1998 Convention, however, those provisions are dampened and provisions become impartial, for example, the criminal jurisdiction, the right of intellectual property and the codes of conducts in Space Station. On the other hand, we sets the "model" up, that is "input of national benefits and ideas ${Rightarrow}$ process of law-making ${Rightarrow}$ output of common benefits, universal ideas and wastes." In the case of applying this "model" to 1988 and 1998 Conventions, we are convinced of enough possibility to understand and explain the legal system of Space Station by this "model." This result awakes us that study of legal system of Space Station according to the "model" influences the fundamental theory of International Law Study: the relation between international law and domestic law. This "model" has possibility to change the theory of relation between from "international law and domestic law" to "domestic law and domestic law through international legal system." In the end, we should reconsider on "policy-oriented jurisprudence" by professor McDougal to use his key words for explanation of concepts in the "model," because his theory contains important suggestions to the study of law-making process and legal system for outer space activities in the near future.