In terms of maritime security, the seas that have more meaning to South Korea are the South China Sea and located more close to the country, the West Sea. A considerable amount of Korea's shipping volume passes through the South China Sea. This makes the US and China demand the position of Korean diplomacy as the US-China conflict in the region deepens which gives many dilemmas to Korean security. Among South Korea's neighboring waters, the South Sea has remained as a region with no territorial disputes following the agreement between Korea and China. In the West Sea, there are problems regarding the Northern Limit Line (NLL) between North and South Korea. There have already been several armed conflicts in this region and the volatility of inter-Korean problems raise tensions in the sea high making it unpredictable when and how conflicts will rise. In this sense, South Korea should keep its present stance of supporting freedom of navigation and promoting peaceful solution on the South China Sea conflict. The NLL controversy is not to be understood as a mere territorial dispute, but as part of the entire issues involving North Korea. Seoul should approach to this problem from its unification policy perspective.