Abstract: Titanium carbide films were prepared on AISI52100 steel substrate making use of metal plasma immersion ion implantation and deposition (MePIIID) and radio-frequency glow discharge technique, using acetylene (C_2H_2) as the working gas and pure titanium cathodic vacuum arc as the metal plasmas source. Thus the TiC thin films were deposited in the intervals between the high voltage bias pulses and the implantation was performed during the pulses. The effect of the implantation pulse width and working gas pressure on compositions and properties of the resulting TiC films as the modified layers were examined, based on the examination of the chemical compositions and microstructures of the TiC films by means of X-ray diffraction. The friction and wear behaviors of the films were evaluated on a pin-on-disc test rig, while the corrosion resistance of the films was investigated using an electrochemical corrosion method. It was found that the surface microhardness of the steel substrate was significantly increased after the modification at proper parameters. Therefore, the TiC films as the modified layers had much better friction-reducing and antiwear abilities than the steel substrate. Moreover, the TiC film also had much better corrosion resistance than the steel substrate. The compositions and microstructures of the TiC films were closely related to the parameters such as the implantation pulse width and working gas pressure. Thus it was imperative to realize the best surface-modification effect of the steel by properly selecting the parameters for the MePIIID.