South of the Yangtze River: Nanjing, Suzhou, Wuxi, Changzhou, Zhenjiang

North of the Yangtze River: Yangzhou, Taizhou, Nantong, Yancheng, Huai'an, Suqian, Xuzhou, Lianyungang

Jiangsu, referred to as "Su", with its capital Nanjing, is located in the eastern coastal center of mainland China and the lower reaches of the Yangtze River. It borders the Yellow Sea to the east, Shanghai and Zhejiang to the southeast, Anhui to the west, and Shandong to the north. It is located between 116°18′～121°57′ east longitude and 30°45′～35°20′ north latitude. The formal establishment of Jiangsu Province began in the sixth year of Emperor Kangxi of the Qing Dynasty (1667). The original Jiangnan Province was split into Jiangsu (including Shanghai) and Anhui Provinces. The Governor-General of the Two Jiangs was stationed in Nanjing, in charge of the military and civil affairs of Jiangsu, Anhui and Jiangxi Provinces. The Jiangsu Governor's Office was located in Suzhou until 1912.

Since 1983, Jiangsu has implemented a city-county administrative system. It currently governs one sub-provincial city, Nanjing, 12 prefecture-level cities, Wuxi, Xuzhou, Changzhou, Suzhou, Nantong, Lianyungang, Huai'an, Yancheng, Yangzhou, Zhenjiang, Taizhou, and Suqian, 23 county-level cities, 22 counties, and 55 districts under the jurisdiction of sub-provincial cities and prefecture-level cities.

The Yangtze River, the largest river in Asia, ranks first in Asia in terms of drainage area, length, and water volume. It originates from the Geladandong Snow Peak, the main peak of the Tanggula Mountains on the Qinghai-Tibet Plateau. The Yangtze River has many tributaries, and the Yangtze River basin is about 3,219 kilometers from west to east and more than 966 kilometers from north to south. The Yangtze River is more than 6,300 kilometers long, making it the third longest river in the world, second only to the Nile River in Africa and the Amazon River in South America in length, and second only to the Amazon River and the Congo River in Africa in water volume, ranking third in the world.

During the late Zhou Dynasty and the founding of the Northern Song Dynasty, the Yangtze River was the boundary between the Southern Tang Dynasty and the Northern Song Dynasty. The Chen Dynasty was the weakest regime in the Southern Dynasties, so weak that it was bounded by the Yangtze River.