A method for producing an alkenylbenzene by catalytically dehydrogenating an alkylbenzene non-oxidatively in the presence of steam in the reaction zone comprising a fixed-bed of potassium-containing dehydrogenation catalyst particles, wherein the potassium-containing dehydrogenation catalyst particles are prevented from powdering by (a) using a fixed-bed comprising particles of at least two kinds of potassium-containing dehydrogenation catalyst with respectively different potassium contents and (b) arranging the catalyst particles so that those with higher potassium content are not disposed on the inlet side of said catalyst bed with respect to the reaction.
