The South China Sea is one of the most important sea lanes with numerous competing sovereignty disputes. The freedom of navigation in this region is critical to all major trading States in the world. After an introduction to the navigational regimes of UNCLOS, this article describes the whole navigation situation in this region, by separately introducing the navigation issues in the territorial sea, straits, archipelagic waters and the Spratly area. Meanwhile, since the legal status of the maritime zones decides the applicable navigational regimes, the validity of the claims of the coastal States in this region ?the historic claims, the claims of archipelagic waters, the characteristic of the straits (whether they are used for international navigation or not) and the claims of the Spratly Islands ?must be justified based on the international law. This article tries to justify the principle claims in this region and find the lawful and proportionate navigational regimes by clarifying the legal status of the specific maritime zones.