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

[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.

[2] In April 1962, Zhoushan was restored to prefecture-level status, and Dinghai County was re-established.

[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.