Currently, locomotives running on railways in mining districts in China are mostly steam engines, the manufacturing of which, however, has been stopped in China, which has led to shortage of spare parts supply, long overhaul period and high repair cost of the steam engines. Being very difficult to enhance the traveling speed and hauling load and causing serious environmental pollution, steam engines no longer satisfy the requirements of mining production and the needs of the national railroad development. Therefore, model renewal of railway engines is pressing in mining districts. A comparison of features and operating costs between diesel engines and steam ones concluded that the former should be a priority for engine model renewal in mining districts.