The present study evaluates the simultaneous adsorption of H2S and/or COS by activated coke in the presence of other gases and the effect of coexisting gases on the adsorption behavior of sulfur compounds. The coexisting gases (H-2, H2O, CO, and CO2) were supplied separately from H2S or COS. The activated coke produced from coal was used as the adsorber in this experiment. While H2S was able to adsorb onto the activated coke on its own, its ability to adsorb decreased significantly in the presence of other gases due to the generation of COS. On the other hand, the adsorption ability of COS improved significantly when H-2, H2O, CO and CO2 were present. This was attributed to the conversion of COS into H2S and the adsorption of COS as H2S in the activated coke.