[1] The ruling grade of the line is 13‰, and the minimum curve radius is 400 m (1,300 ft).

The Namsi (now Yŏmju)–South Sinŭiju stretch of railway via Paengma was opened on 28 April 1905 by the Temporary Military Railway as part of the mainline of the Kyŏngŭi Line from Kyŏngsŏng (Seoul) to Sinŭiju.

On 16 October 1943, South Sinŭiju Station became a connecting station with the Sinŭiju–Yangsi–Namsi Yangsi Line, which the Chosen Government Railway had taken over from the privately owned Tasado Railway on 1 April of that year.

[3] After the establishment of the DPRK and the nationalisation of its railways to create the Korean State Railway, the line from Ryongch'ŏn (formerly Yangsi) to Yŏmju (formerly Namsi) remained separate as the Yangsi Line.

There is extensive freight traffic on the line, serving the large Ponghwa Chemical Complex at Paengma and several other factories.