CH. Karnchang Public Company Limited, together with its subsidiaries, provides construction services in Thailand and the Lao People's Democratic Republic. It operates through Construction and Related Service; and Investment in Infrastructure Business segments. The company engages in the construction of mass rapid transit systems, airports, roads and expressways, energy projects, water supply and harbor projects, and buildings. It also invests in infrastructure project development business; and engages in the sale of construction materials. The company serves government agencies and private customers. The company was founded in 1972 and is based in Bangkok, Thailand.