Cao'e River, the forbidden word tributary of the Qiantang River that flows into the East China Sea alone, was named after the Eastern Han Dynasty girl Cao'e entered the river to save her father. The vicinity of Shengzhou is also called Yanxi, Shangyu is also called Shangyu River, the vicinity of Baiguan is called Shunjiang in ancient times, and the downstream section is called Dongxiaojiang in ancient times.

The Cao'e River is the last important tributary that flows into the Qiantang River. Most of the rivers are important industrial and agricultural water sources along the coast. There are water diversion projects such as the Shangpu Sluice. The downstream shipping capacity is strong, of which Cao'e Port is an important port. The estuary is greatly affected by sea tides, and the famous Cao'e River sluice junction project has been built to prevent tides (floods) and control waterlogging.