Adsorption of n-olefins (less than or equal to C-4) on a ferrierite (FER) zeolite was observed by infrared (IR) spectroscopy. Ethene and propene adsorbed selectively on the acidic OH (OD) groups in the small pores of FER, while butenes adsorbed also on the silanol groups on the external surface at ca. 200 K, a part of which transferred to tbe;acidic sites upon increase in temperature. This indicates the existence of energy barriers for intercalation of butenes into the FER pores. The facility among butenes for migration to the FER pores was found to be in the order trans-butene > 1-butene > cis-2-butene.