The subject of this paper is to analyse the level of international environment security in the South China Sea region in the 21st century, especially from the perspective of the two most important international relations of the PRC and the United States. It is noted that Beijing gradually takes over the initiative, which is reflected in the development of the abilities of the armed forces, especially of the navy, and the development of economic policies in the region, which gradually draws and makes individual states in the region dependent. At the same time, there is a gradual decline in the role of the United States in South East Asia, the primary purpose of which in terms of “the policy to prevent and restrict China” is to create a block of East and South East Asian states able to confront Beijing’s possible expansion tendencies under Washington. It is noted that Beijing gradually takes over the initiative as the shape international environment center in the region.