The thermal desorption of benzene, cyclohexane, methanol and ethanol from NaY and LiY zeolites has been studied to obtain information on the adsorbate-adsorbent interaction. The desorption rates of these hydrocarbons were measured with thermal conductivity cell increasing the desorption temperature from 50^o to 400 ℃ with various constant heating rates. Activation energy of desorption was determined from the desorption curve, assuming the desorption rate is first order with respect to the surface coverage. The activation energy of benzene increased rapidly but that of alcohol did gradually as the surface coverage decreased. Experimental results showed that these four hydrocarbons were strongly adsorbed on LiY rather than NaY. Data also revealed that the interaction of benzene with zeolites was stronger than that of cyclohexane and the interaction of ethanol was stronger than that of methanol.