Yangtze Delta, generally comprises the triangular-shaped territory of Shanghai, southern Jiangsu province and northern Zhejiang province. The area lies at the heart of the region traditionally called Jiangnan (literally: "south of the Yangtze River"). The Yangtze river drains into the East China Sea.

History
The area near the Yangtze River Delta was the location of the Majiabang neolithic culture from around 5000-3000 BC. In late Neolithic times, the delta was the site of the Liangzhu jade culture (3400-2250 BC). In the Spring and Autumn period, it was occupied by the State of Wu, which was annexed by the State of Yue in 473 BC, in turn conquered by the State of Chu in 334 BC. In 223 BC the area became part of the unified empire under the Qin Dynasty.

Since the Tang Dynasty, the Yangtze Delta has been an area of intense agrarian agriculture and high population density. It is criss-crossed with canals for transportation and irrigation. Since the Northern and Southern Dynasties period, the Yangtze Delta has been a main cultural and economic center of China. Key cities of the region in pre-modern times include Suzhou (Wu), Nanjing, Hangzhou and Shaoxing.

In modern times, the Yangtze Delta, lead by Shanghai, is the center of Chinese economic development, and surpasses all other regions in the People's Republic of China in terms of economic growth and per capita income.

Population
The delta is one of the most densely populated regions on earth, and includes one of the world's largest cities on its banks—Shanghai, with a density of 2,700 inhabitants/km². Because of the large population of the delta, and factories, farms, and other cities upriver, the World Wildlife Fund says the Yangtze Delta is the biggest cause of marine pollution in the Pacific Ocean.

The people in this region mainly speak Wu Chinese (commonly called Shanghainese) as their mother tongue. Wu Chinese is mutually unintelligible with Mandarin.