Adsorption and desorption of ethylene and benzene on various adsorbents were performed in a flow system. Ethylene was weakly adsorbed on activated carbons and zeolites, and it was reversibly desorbed under helium atmosphere. Compared to ethylene, benzene was strongly adsorbed on the adsorbents. Adsorption performance for both ethylene and benzene was the best on purified AC. It is considered that purified AC can be applied to a adsorbent for the adsorption-catalytic oxidation system.