Changjin produces large amounts of lumber, and leads the province in mine production. Deposits of silver, graphite, jade, and gold are found in the area. Local agriculture is dominated by livestock raising and dry-field farming; local crops include potatoes, barley, soybeans, red beans, maize, and oats.
Although it could long be reached only by horse or automobile, the construction of a power plant on the Changjin River also brought the Changjin Line of the Korean State Railway to the county. Water transportation also developed thanks to the power station.