Methane formation and surface composition change of a TiC coating are studied under hydrogen ion bombardment by means of residual gas analysis and Auger electron spectroscopy. Hydrogen ion energy is between 500 and 3 keV and the target temperature ranges from room temperature to 1000 °C. The methane emission yield is minimum (2–4)×10−3 molecules/ion, near 500 °C and is increased by a factor of 2–3 in room temperature and 1000 °C. The surface composition during hydrogen ion bombardment is quite dependent on both the target temperature and the ion energy. Concerning the temperature effect, the ratio of carbon to titanium atoms of the TiC surface after ion bombardment at room temperature is lower than that at 590 °C. Concerning the energy effect, the C/Ti ratio decreases with lower bombardment energies.