The Battle of Tangdao is a naval engagement that takes place in 1161 between the Jurchen Jin and the Southern Song Dynasty of China on the East China Sea.

The conflict is part of the Jin-Song wars, and is fought near Tangdao Island.

It is an attempt by the Jin to invade and conquer the Southern Song Dynasty, yet results in failure and defeat for the Jurchens.

The Jin Dynasty navy is set on fire by firearms and Fire Arrows, suffering heavy losses.

For this battle, the commander of the Song Dynasty squadron, Li Bao, faces the opposing commander Zheng Jia, the admiral of the Jin Dynasty.

This battle is followed almost immediately by another naval confrontation, the Battle of Caishi .

The battle is significant in the technological history of the Song navy.

The Song naval forces are further reinforced by the aid of seafaring Chinese merchants.

The technological gains of the Song navy ensure its access and dominance of the East China Sea for centuries in competition with the military forces of Jurchen and Mongol rivals.

By 1129, the Song navy had invented gunpowder bombs for warship trebuchets.

The weapon is made mandatory for all ships in the Song fleet.

The construction of paddlewheel ships, operated with treadmills, goes on for several decades between 1132 and 1183.

The engineer Gao Xuan devises a paddlewheel ship outfitted with up to eleven paddle-wheels on each side.

Iron plating for armoring the ships is designed in 1203 by the engineer Qin Shifu.