根据史料记载，自汉朝以来，中国历朝对南海都有巡海安保的专门负责部门。如今大家都知道，南中国海上的众多岛屿蕴藏丰富的石油天然气资源，同时也具有重要的战略地位，这就引起争端了。
gēnjù shǐliào jìzǎi ，zì Hàncháo yǐlái ，Zhōngguó lìcháo duì nánhǎi dōu yǒu xún hǎi ānbǎo de zhuānmén fùzé bùmén 。rújīn dàjiā dōu zhīdào ，nánZhóngguóhǎi shàng de zhòngduō dǎoyǔ yùncáng fēngfù de shíyóu tiānránqì zīyuán ，tóngshí yě jùyǒu zhòngyào de zhànlüè dìwèi ，zhè jiù yǐnqǐ zhēngduān le 。
According to historical records, from the Han Dynasty onward, Chinese dynasties have a government organ responsible specifically for patrolling the South China Sea for security threats. It is commonly thought that many of the islands and reefs in the South China Sea hold rich reserves of oil and natural gas. At the same time, they are also important strategic locations, leading to the disputes.