Siouguluan River ( 秀姑巒溪; Pe̍h-ōe-jī: Siù-ko͘-lôan-khoe) is a river in southeastern Taiwan. It flows through Hualien County for 104 km (65 mi) before emptying into the Pacific Ocean.
The river originates on the eastern side of Mabolasih Mountain (on the border with Taitung County) and flows through the Siouguluan Mountain. It is the largest river in eastern Taiwan. Over 30 species of fish have been found in the river.
he river is known for its many rapids and has become a prime destination for rafting, especially on a 24 km (15 mi) section Rueisuei Bridge to the Changhong Bridge.