Ruxu (濡須) was a fortified position and anchorage on the Yangtze in Yang Province, facing the approaches from the Huai basin. Sun Quan strengthened it as part of his river defence line.
In 213–214 Cao Cao advanced to the river and attacked Ruxu in the Battle of Ruxu. Sun Quan personally oversaw the defence; generals such as Gan Ning and Dong Xi held the line. After months of fighting, Cao Cao withdrew, and the Yangtze continued to mark the border between north and south.