Nanji Islands National Nature Reserve is located in the east part of Pingyang County, Zhejiang Province. It covers a total area of 201.06 square kilometers, among which sea waters account for 190.71 square kilometers. Its center is located at 27°27"N, 121°25"E. It is 56 kilometers away from Aojiang Port of Pingyang County and about 150 kilometers away from the Taiwan Island. The biggest island of the Reserve is the Nanji Island with an area of 7.64 square kilometers, and that's why the Reserve was named after it. The Reserve lies in the transitional part of temperate and tropical zones, and its location is in a coastal area where the Taiwan warm current and Jiangsu-Zhejiang coastal current fluctuate in alternation. It proves to be an ideal place for sea life. Established in 1989 after the approval of Pingyang County Government, the Reserve, the first one of its kind, was classified as a national reserve in 1990. The shellfish, algae and the natural environment are the main targets for protection. In July 1998, Nanji Islands National Nature Reserve was approved by the UNESCO as a member of the International Man and Biosphere Reserve Network.
Nanji Islands National Nature Reserve lies in a coastal area where the Taiwan warm current and Jiangsu-Zhejiang coastal current fluctuate in alternate. Climate of the region is oceanic monsoon climate, so it is temperate without being too hot in the summer and too cold in the winter with an average annual temperature of 16.5℃.
Most parts of the Reserve are washed and eroded by seawater, and the coastline there is tortuous. The Nanji Island is a bedrock island mainly composed of 23 islands and 14 reeves. The Nanji Island, the biggest one in the Reserve covering an area of 7 square kilometers, looks like a muntjac with its head northwestward and tail southeastward. The highest peak of the Nanji Island is 229 meters above sea level.
The Nanji Island is surrounded by 5 capes including Longzhuitou Cape, 3 bays including Mazu'ao Bay and Niji Port. There is a shellfish sea beech along the island, 800 meters wide and 600 meters long. The sea there is so limpid and transparent that one can see 5 meters deep into the water. Rocks washed and eroded by waves for a long period of time make up a picturesque landscape of cliffs, pillars, caves and terraces. They are appraised as fairy hills over blue sea.