Systematic studies have been made of the causes of loss of activity of zeolite catalysts in the alkylation of isobutane with butenes. It has been established that rapid loss of catalytic activity in this reaction is connected with transformation of the active centre of the catalyst and primarily with its Lewis component. The possibility of lengthening the operating time of zeolite catalysts for the alkylation of isobutane with butenes by their modification with palladium and also by separating the catalyst bed itself has been shown.