As an acid-catalyzed reactions, the isomerization of 1-butene, the transformation of o-xylene and the dehydration of ethanol over the transition metal ion(Cu²⁺, Ni²⁺) exchanged zeolites were carried out to compare with Ag⁺ ion exchanged zeolite. Hydrogen enhancing effect and its reversibility, the effect of reduction and reaction temperature, partial pressure of hydrogen, the type of metal ion, the type of zeolite, ion exchange ratio were studied to the catalytic activity. The reversible hydrogen enhancing effect on the catalytic activity was observed over the hydrogen reduced Ag⁺ and Cu²⁺ ion exchanged zeolites by the presence or absence of hydrogen in the reaction system. This means that hydrogen was reversibly chemisorb-ed and retained as an acidic protons on those zeolites. But, the selective hydrogenation of 1-butene was occurred over the hydrogen reduced Ni²⁺ ion exchanged zeolite by the presence of 1-butene was occurred over the hydrogen reduced Ni²⁺ ion exchanged zeolite by the presence of hydrogen. Also, the shape-selectivity of product in the 1-butene isomerization was observed with the type of zeolite.