The Pearl River is the third largest river in China, next to the Yangtze River and the Yellow River. Formed at Guangzhou by the confluence of the Xijiang, Beijiang and Dongjiaing rivers, it flows through Kunming, Guizhou, Guangdong, Guangxi, Jiangxi and Hunan provinces. The river links Guangzhou to Hong Kong and the South China Sea, and is one of China's most important waterways and one of the centers of its world trade. The total length of its trunk and tributaries is about 11,000 kilometers, with a drainage area of 452,600 square kilometers.

The Xijiang River, originated in Maxiong Mountain of Yunnan Province, is the trunk, with 2,210 kilometers long; the Beijiang River, originated in Jiangxi Province, stretches 468 kilometers, with an drainage area of 46,000 square kilometers; and the Dongjiang River, originated in Jiangxi Province, stretches 523 kilometers, with an drainage area of 28,000 square kilometers.

The Pearl River is the largest river in southern China, with an annual runoff of 341.2 billion cubic meters, of which the Xijiang River accounts for 80 percent, with an annual runoff of 267 billion cubic meters. The Beijiang River only has an annual runoff of 47.2 billion cubic meters, and the Dongjiang River, only 27.2 billion cubic meters. In terms of the runoff volume, the Pearl River is considered the second largest in China, next to the Yangtze River. It has enormous hydroelectric resources, with an annual potential of up to 33.35 million kilowatts, taking up 58 percent of the total amount of the country.