Caoba–Guanjiashan railway, or Caoguan railway (Chinese: 草官铁路) is a short 1,000 mm (3 ft 3+3⁄8 in) railway in Yunnan Province of China, a branch of the 1,000 mm (metre-gauge) Kunming–Hekou railway (the Chinese section of the Kunming–Hai Phong railway). It is 31.9 km long. It connects on the Kunming–Hekou railway with , a dead-end station in of Gejiu City. It also serves as the connector between the Kunming–Hekou railway and the Mengzi–Baoxiu railway. The Caoguan railway is located entirely within the administrative borders of the cities of Mengzi and Gejiu.