Abstract: Titanium carbide coating with appropriate thickness (10-15μ)is possessed of some excellent properties such as high melting point, high hardness, low coefficient of ,sliding friction and appropriate anticorrosive,property. Thus it, may be used for special,purpose. But the CVD of TiC ,still encounters the following problems, which limit the field of its application. 1: The temperature of CVD process is too high even higher than 1100℃. At this temperature the grains of steel will be coarsened and hence the properties will become deteriorated. 2. Since the difference of the coefficient of thermoexpansion between the TiC coating and steel is so great that the cohesion between the coating and the substrate is not quite strong. 3. In order to increase the loading ability of the work pieces; we must find out a method to improve the strength of the substrate below the CVD coating. A thermodynamic analysis of some of chemical reactions of the CVD process is demonstrated in this paper. On the basis of this analysis the authors suggest the using of some titanium sponge in reaction chamber and also the using of carbon tetrachloride instead of hydrocarbons as carbon supplier of CVD process of TiC. On the above suggestion the temperature of the CVD of TIC on steel may be lowered to 900℃ or even to, less than 900℃.If work pieces undergo a suitable chemical heat treatmant first, a transition layer may be formed between the TIC coating and substrate during following CVD process. The existence of the transition layer may lessen the difference of ;the coefficient of thermoexpansion between the TIC coating and the substrate, so that the cohesive strength between them will increase by 30%.The authors have successfully increased the strength of the substrate of the work pieces by reheating them in a fully: deoxidized salt bath and quenching them in an alkaline bath.This technique has been used in the production of a number of tools and machine parts,the working life of which has been proved to be a greatly prolonged.