The Jiajing Railway (Chinese: 嘉镜铁路, shortened form of Jiayuguan–Jingtieshan Railway; Chinese: 嘉峪关镜铁山铁路), officially the Jingtieshan Branch Line (Chinese: 镜铁山支线), is a 69 km (43 mi)-long branch line of the Lanxin Railway in Gansu Province, China.

[1] The railway line mostly runs through rural Sunan County and connects Jiayuguan City with the Jingtieshan iron mine in the Qilian Mountains south of Jiayuguan.

The route follows the course of the Beida River (Chinese: 北大河) through the Qilian Mountains before reaching the Gobi Desert outside of Jiayuguan.

Originally serving only the Jingtieshan mine operated by Jiuquan Iron and Steel Group Company [zh], the line now also serves the Xigou mine via a short spur.

In addition to the transport of goods, the railway serves as a passenger line primarily for mine workers from Jiayuguan.