TiN films were deposited on aluminum and stainless steel substrates by are ion plating (AIP). Bias voltages, nitrogen gas pressures and are currents were changed to examine their role on the hardness and residual stress of a TiN film. Vickers microhardness tests revealed high hardness value (HV = 2250-2500) which depends on both nitrogen gas pressures and are currents. From the X-ray diffraction pattern, it was found that the crystal orientation of the TiN film markedly varied with the bias voltage. Residual stresses in the TiN film were measured by the two-exposure X-ray stress analysis as a function of the nitrogen gas pressure, are current. Very high compressive residual stresses, -5 GPa in the films on aluminum substrates and -7 GPa in the film on a stainless steel substrate, were observed.