A method for producing butadiene from 2,3-butanediol with high selectivity without using a radioactive substance is disclosed. The method for producing butadiene comprises the step of dehydrating 2,3-butanediol in the presence of a catalyst containing an alkali metal salt of phosphoric acid such as an alkali metal dihydrogen phosphate supported on silica. Preferred examples of the alkali metal herein include K, Rb, and Cs. The catalyst is preferably a catalyst prepared by calcination of the silica to which the alkali metal of phosphoric acid is attached.