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, and the war in the north after the Tang Dynasty intensified this trend. Later, after the development of generations of immigrants, the Jiangnan area has gradually become 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, and drainage is carried out during waterlogging and irrigation is carried out during drought. Together with local crops, it has gradually become a world granary, and is called "Suzhou Lake is ripe and the world is full".