Activated carbons impregnated with cuprous chloride were prepared to separate carbon mono-xide from gas mixture. Adsorption equilibrium experiments were performed for carbon monoxide and carbon dioxide. From these experimental results, adsorption equilibrium isotherms were obtained for each adsorption system. Each adsorption systems can be represented by FH-VSM adsorption equations with the parameters obtained from the experimental result. Amount of carbon monoxide adsorbed on adsorbents increased with impregnation concentration of cuprous chloride on activated carbon up to 37wt%, but decreased above impreg-nation concentration of 37%. These adsorbents which show good reappearance of adsorption in recycling experiments could be used for a TSA process.