Yongxing Island belongs to Xuande Islands in the east of Xisha Islands in China. It is a coral island formed by the accumulation of white coral shellfish sand on the reef platform. It is oval, with a length of about 1.950m from east to west and a width of about 1.350m from north to south, with an area of 2.6km2 and an average elevation of 5m. It is the largest island in the Xisha Islands and the 26th largest island in the South China Sea.

Yongxing Island is the economic, military and political center of Xisha Islands, Nansha Islands and zhongsha islands. It is the residence of Sansha Municipal People's Government, several higher authorities, municipal units and Yongxing Working Committee Management Committee. There are government buildings and schools on the island? Banks, post offices, hospitals, shops, guest houses and libraries? Airports, docks and ports, weather stations, garrisons, etc. With perfect production and living facilities, it is a veritable island new city.