The section from Hsinchu to Chutung, known as the Chutung Line, was opened in 1947. In 1950, the line was extended to Hohsing for the benefit of the limestone quarrying industry. It was further extended to Neiwan in 1951 to serve the lumber and mining industries around Mt. Chienshih, giving the line its current total length of 27.9 kilometers.
這條因應竹東工業區而修築的鐵路，於民國三十六年首開新竹至竹東路段，當時稱「竹東支線」；民國三十九年，因石灰石礦開採的需要，延伸至合興；民國四十年再因尖石山區木材與煤礦運輸，開通到內灣，全長二十七・九公里的支線鐵道就從此底定。