The effect of quenchant temperature on the surface residual stress was studied for AISI 8620 steel. Specimens were carburized at 900℃ in all case type furnace using a gas-base atmosphere of methanol cracked and liquefied petroleum gas, and then subjected to single reheat quenching in oil or salt bath in the temperature range of 60℃ to 300℃. After carburizing and reheat quenching, residual stress was measured by the hole drilling method. Experimental results showed that the surface residual stress was increased as the quenchant temperature was raised. This is in contrast to the fact that the formation of phase of low transformation strain such as bainite results in lower surface compressive stress. The greater compressive stress observed in specimens quenched at higher temperature may be attributed to the shifting of the transformation start point farther from the surface, as was reported in other carburizing steels.