The corrosion behaviour of Inconel-600 was investigated in hydrogen sulphide gas environment at a temperature of 800 degrees C under atmospheric pressure. The apparatus used was a tubular furnace in which the sample was kept and the hydrogen sulphide gas was passed at a high temperature. It was found that the sulphidation in an atmosphere of hydrogen sulphide gas at temperature of 750 degrees C followed the parabolic Fate law. Scale formation was also observed. X-ray diffraction study revealed that the surface consisted mostly of nickel suphide. It was found that at temperatures above 850 degrees C the Inconel-600 alloy got totally corroded in the presence of hydrogen sulphide.