On the vast sea surface south and east of Hainan Island, there are many coral reef islands, mainly including dongsha islands, Xisha Islands, zhongsha islands and Nansha Islands, collectively known as the South China Sea Islands.

The islands of the South China Sea are scattered in the vast abdomen of the South China Sea. In shipping, they are the throats of the Pacific Ocean and the Indian Ocean, the hub of shipping between the two oceans, and the relay station of Asia and the Pacific. In the Ming Dynasty, Zheng He, a famous navigator in China, led his fleet to the Western Ocean for seven times and passed through the South China Sea Islands many times.

South China Sea Islands surround the south of China, just like numerous blockhouses, controlling the vast sea surface of the South China Sea. They can be used as offshore production bases to provide fresh water for ships and meteorological information at ordinary times. In wartime, it can be used as a base and relay station for ship and aircraft activities, effectively controlling and blocking the air and sea passages in the South China Sea, and safeguarding the mainland security of the motherland. Nansha Islands

Nansha Islands, located at the southernmost tip of the South China Sea Islands, have the widest scope and the largest number of islands and reefs. There are mainly islands and reefs and sandbars such as Taiping Island, Nanwei Island, Zhongye Island, Nanzi Island, Beizi Island, Hung Hom Island, Jinghong Island, Feixin Island, Mahuan Island, Anbo sandbar, Yongshu Reef and Zengmu shoal. 1988, China built an artificial island with an area of 8,080 square meters on Yongshu Reef, and an ocean observatory was built on the island. Five nearby islands and reefs, including Chigua Reef, were also guarded by our navy.