This article examines the legal status of the Democratic People’s Republic of Korea (North Korea) from the perspective of international law. In the process of unification international legal issues will be raised, including succession of treaties, membership in the international organizations, and liquidation of State debts. To resolve this complicated set of legal problems, the primary issue would be affirmation of the legal status of North Korea. Indeed, North Korea is not considered as a recognized ‘State’ from the perspective of national law of the Republic of Korea (South Korea). According to Article 3 of the Constitution, the sovereignty of the Republic of Korea extends over the entire Korean Peninsula, and North Korea is an unlawful group illegally occupying the northern part of the territory. Thus, the relationship between South and North Korea is not that between two ‘States’ but is considered in terms of ‘special relations.’ However, viewed externally, North Korea is a sovereign State satisfying all required elements for statehood in inter- national law: there certainly is a population living in a defined territory that a government effectively controls. Moreover, North Korea is engaged in various international legal relations, bilateral and multilateral, and also is recognized by various States. Thus, from the external perspective, the unification of South and North Korea would be not the restoration of effective control over a region that has been impeded by an unlawful opposition group due to its occupation of the territory. It would be a case where two legal persons merge into a single legal person either by way of extinction of one party by absorption, or extinction of two legal persons into a single legal person by an agreement. Although South and North Korea are determined to deal with their relationship not as a relationship between two States but as an internal matter of the Korean people, this rationale could not always be enforced when a third party is engaged in this issue. Through an examination of the legal status of North Korea from the perspective of international law, this article attempts to provide objective understanding of the international legal status of North Korea in order to prepare for possible international legal issues that may be raised in the course of unification.