International Law has reign most interactions between States in the sea. The practice of illegal transshipment is a serious issue as it falls within both theft mode and smuggling through the transfer of cargo from one ship to another that occurs at sea. Including a crime which committed in the territory of one state but involving parties from another state or more. Dispute on the South China Sea, Especially on the two groups that spratly and paracell involving 6 countries such as China, Taiwan, Vietnam, the Philippines, Malaysia and Brunei. The military activity spike in the disputed area generated a lot of the incidents between military force. Obscurity of area ownership and high activity of the military could jeopardize security and order in. The research analyses the legal status of South China Sea and whether placement of each country military force in the dispute on the south china sea was justified by international law. The results of this research showed that Freedom of Navigation s one of the main principles of UNCLOS 1982. However, n fact dozens of ships with the PRC flag are not only sailing, but fishing llegally. On the other hand, CCG also entered the EEZ, accompanying the fishing vessels with the aim of guarding and protecting them from all forms of disturbance, ncluding from the actions of ndonesian law enforcement vessels. at least two violations occurred. First, the violation of ndonesia's sovereign rights by China fishing vessels. Second, the CCG's actions that hinder the law enforcement of the Republic of ndonesia as regulated n Article 73 (par. 1-4)The study aims to determine the jurisdiction of states in enforcing laws including in criminal matters that occurred over its sea where the country has sovereign rights, especially when the involvement of 3rd states party in the law enforcement on a ship which not entered into its territory, yet indicately committed a violation of the law in some states water area, this paper also study how the responsibility of 3rd states party towards of flag states of ships who feel harmed. This article was written using normative research methods with a statutory, historical and conceptual approach explaining efforts from international organizations in resolving the issues of accountability of countries involved in the problem of Illegal Transshipment at sea in the 1982 UNCLOS perspective especially the process of law enforcement and dispute resolution by the International Tribunal for the Law of The Sea (ITLOS).