Chongming Island is a shifting, man-made geography that defies traditional borders and maps.

Countries & Cities · Published 30 September 2026 Swipe more like this →

In short: Rising from the Yangtze River's mouth, Chongming Island is a geological chameleon. Once a collection of unstable, wandering shoals, it has been stitched together by centuries of sediment and human engineering. Today, this massive alluvial landmass hosts a bizarre political anomaly: two pockets of Jiangsu province embedded within Shanghai.

Chongming Island began as two separate shoals, Xisha and Dongsha, during the Tang dynasty's Wude Era (618–626). For centuries, the island's existence was precarious; the Yangtze's floods caused shoals to appear, erode, or vanish entirely. By the late 17th century, a series of mergers unified various landmasses, creating the foundation of the modern island. This process of accretion has been dramatic: large-scale reclamation projects in the 1960s and 1990s effectively doubled the island's total land area between 1950 and 2010.

The island's political geography is equally fluid. While it is the northernmost district of Shanghai, it contains two pene-exclaves belonging to Jiangsu province: Haiyong and Qilong. These areas emerged from the island of Yonglongsha, which appeared in the Yangtze in 1937. Workers from Nantong, Jiangsu, stabilized and expanded these lands in the late 1960s. Qilong was connected to Chongming in 1972, followed by Haiyong in 1975. Today, these enclaves remain under Jiangsu's administration, creating a complex jurisdictional patchwork on the island's northern shore.

Modern Chongming is no longer the isolated, ferry-dependent outpost it once was. The G40 Expressway now links the island to the mainland via the Shanghai Yangtze Bridge and Tunnel, and further infrastructure projects—including the Chonghai Bridge and the planned 2026 extension of Shanghai Metro Line 22—are rapidly integrating the island into the urban fabric of Shanghai. Despite this development, the island maintains significant ecological zones, such as the Dongping National Forest Park, which covers 3.55 square kilometers of artificially planted trees, and the Dongtan Nature Reserve, serving as a critical habitat for endangered species like the finless porpoise.

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