In terms of maps, Zheng He's "seven voyages to the Western Seas" in the Ming Dynasty had been sailing for a long time, drawing Zheng He's nautical charts, which were later included in Wu Bei Zhi by Mao. Icons show the names and relative positions of Shixing Shitang, Wansheng Shitangyu, Shitang and other island groups. By the Qing Dynasty, the attached map "General Plan of the Four Seas" in Chen Lunjiong's "Records of the Seas" had clearly marked the place names and locations of the four major islands. At that time, dongsha islands was called Qishatou, Xisha Islands was called Zhou Qiyang, Nansha Islands was called Shitang, and zhongsha islands was called Changsha. Later, the Qing government compiled various maps on the basis of a large-scale national map survey. 17 16, the whole map of Qing dynasty at home and abroad, 1724, the sub-map of Qing dynasty, 1767, the unified map of the world in the first year of Qing dynasty, 1800, the general map of Qing county hall, 65433.
As far as ancient books are concerned, the followers of Zheng He's "seven voyages to the Western Seas" wrote Star Check Blue Star, Ma Ci's Ying Ya Sheng Lan, and Gong Zhen's Xi Yu Ji, among which the records about the South China Sea and the islands in the South China Sea left us valuable information. The navigation works at that time, such as Yu Lu in Haicha by Gu Yan 1527 and Yu Hai by Huang Zhong, described the navigation, island reef distribution and geographical features of the South China Sea in detail. All coastal defense projects at that time regarded the South China Sea Islands as the "gateway" and "natural barrier" of China's coastal defense. For example, in the book Outline of Coastal Defence in 1930s, Xisha Islands and other islands were listed as coastal defence areas of China.
As far as local chronicles are concerned, Ming and Qing dynasties are the heyday of local chronicles. Many local chronicles compiled by the government, such as Guangdong Tongzhi, Qiongzhou Prefecture Records, Wanzhou Records, etc. , which contains information of southwest zhongsha islands, is listed as an affiliated island of Hainan Island. Guangdong Tongzhi records that Zheng De set up a coastal defense camp in Wanzhou in the seventh year (A.D. 15 12). It can also be seen from Zheng De's Qiongtaizhi that Xisha and Nansha Islands were regarded as coastal defense areas of China at that time.