The Sŏho Line is an electrified 762 mm (2 ft 6 in) narrow gauge railway line of the Korean State Railway in Hamhŭng-si, North Korea, running from Hamhŭng to Hŭngnam and Sŏho.

[2] After the defeat of Japan in the Pacific War and the subsequent partition of Korea, the entirety of the line, being north of the 38th parallel, was located in the Soviet zone of occupation; on 10 August 1946, the Provisional People's Committee for North Korea nationalised all railways within its jurisdiction, including the Namhŭng Line, and it has since been operated by the Korean State Railway.

When Naeho Station was closed, the line between Hadŏk and Sŏho was realigned to the current, shorter alignment.

The pink background indicates that that section is electrified 762 mm (2 ft 6 in) narrow gauge.

These locomotives underwent complete body replacement by the 8 February Vinylon Factory and the Hamhung Narrow Gauge Office in 2017 and received a blue and white exterior along with the reconstruction of the line.