The Yangzhou section of the Grand Canal was an important place for the Caoyun system and the transport of tribute grain, a main route for the circulation of salt and a distribution centre of salt.

The Han Ditch dug near present-day Yangzhou by the state of Wu in 486 BC is the first canal whose year of digging can be found in Chinese historical records. In the Ming and Qing dynasties, the reform of the salt monopoly further promoted the development of Yangzhou. During the Kangxi, Yongzheng and Qianlong reigns, extensive manpower and material resources were used to further dig and improve the Grand Canal, maintaining smooth traffic on the Grand Canal and securing the prosperity of the Caoyun system and the transport of salt. Yangzhou became more important in transport, becoming a hub of transport and a supply base and distribution centre of salt in the Qing dynasty.