It is recorded in Vol. 21 "Maritime Channels·Coastal Defense" of Qiong Tai Zhi, the book of the Ming Dynasty (AD 1368-1644) that, "In the twentieth year of Hongwu, the pirates landed in Haikou, and Hua Mao the commander submitted a petition to the emperor about establishing a castle, to be manned by soldiers from the Thousand-household Bureau.
In the Qing Dynasty (AD 1636-1912) local officials had a clear understanding of the significance of coastal defense, as reflected in Annals of Xin'an County, "Of military affairs, border defense is most urgent.
In Qiong Zhou Fu Zhi, the book written by Ming Yi in the Qing Dynasty (AD 1636-1912), the tract of seas controlled by the navy of Yazhou in the Daoguang Era was described as "spreading in the east from Dong'ao Port in Wanzhou to Sigengsha in Changhua County in the west, covering 1,000 li.
According to Quan Zhou Fu Zhi of the Qianlong period in the Qing Dynasty (AD 1636-1912), deputy governor of Guangdong started an inspection of the South China Sea from the current Haikou.
In 1909 (the late Qing Dynasty), Li Zhun, the Navy Admiral of Guangdong led the three warships of Fubo, Chenhang and Guangjin on an inspection tour of Dongsha Qundao, Xisha Qundao.