It is based on the larger northwestern half of Zhoushan Island, where it borders Putuo in the east.

The district boundary meets that of Daishan County out at sea to the north of the island.

[2] During the Spring and Autumn period, the area was known as Yongdong (甬东; 甬東), and belonged to the Yue state.

[2] In 1073, the area was organized as Changguo County (昌国县; 昌國縣), and was placed under the jurisdiction of Ming Prefecture.

[4] Dinghai was handed back by Charles Elliot, but was subsequently re-captured by Henry Pottinger, on October 1, 1841.

[5] Located in northeast Zhejiang Province, southeast Shanghai, Hangzhou Bay, the outer edge of the East China Sea.

[5] Many of the islands have hilly terrain, and the highest point in the district is Huangyanjian Mountain (黄杨尖山), which reaches 503.6 meters in altitude.

[6] The endangered black-faced spoonbill, the yellow-billed egret, the horned grebe, and other species of birds are also native to the island.

[6] North subtropical southern margin of the marine monsoon climate, warm in winter and cool in summer, mild and humid, plenty of light.