During the Southern Song Dynasty, "Su Hu connected with the world" indicated that Taihu Lake Basin had become the most important granary in China.

Since the late Tang Dynasty, China's economic center of gravity has been moving southward, which was further aggravated by the war in the north after the Tang Dynasty. Later, after generations of immigrant development, the Jiangnan area gradually became rich. During the Southern Song Dynasty, the Southern Song Emperor vigorously developed and repaired water power. After the completion of water conservancy facilities, lakes and canals are densely covered, drainage is carried out during waterlogging and irrigation is carried out during drought. Coupled with local crops, it has gradually become a granary in the world and is known as "Suzhou Lake is ripe and the world is full".