Abstract: The results of the application of carburizing atmosphere formed in situ from organic liquids are introduced. It was shown that the carbon potential of this atmosphere can be controlled, and the carburizing process is easy to operate with lower energy consumption. The quality of the products is reliable.Based on the equilibrium of multiphase reactions, the compositions of four furnace atmospheres which are produced from air with propane, air with benzene, air with benzene-alcohol, and air with kerosene respectively were calculated.It was found through calculation that the variation of composition of the cauburizing atmosphere due to the change of the mixing ratio is an important factor responsible for the fluctuation of the carbon potential when a single parameter control system is used. The degree of this fluctuation is a reflection of the controllability of the atmosphere.With proper selection of appropriate agent, controlling parameter, and air flow rate, the controllability can be imprqved.Based on the calculation of the furnace atmosphere, a appropriate selection of the agent and controlling parameters can be made.