The dehydration of ethanol into ethylene was investigated over various solid acid catalysts, such as zeolites and silica-alumina, at temperatures ranging 453-573 K under atmospheric pressure. Ethylene was produced via diethyl ether during the dehydration process. H-mordenites were the most active for the dehydration. It was suggested that the catalyst activity could be correlated with the number of strong Bronsted acid sites in the catalyst. Further, the H- mordenite was more stable with a SiO2/Al2O3 ratio of 90 than with a SiO2/Al2O3 ratio of 20.