An object of the present invention is to provide a method for producing 5-hydroxymethyl-2-furfural (5-HMF) suitable for industrial-scale production and a novel catalyst composition for use in synthesizing 5-HMF. The present invention provides a method for producing 5-HMF comprising performing a dehydration reaction of a carbohydrate comprising a hexose as a constituent sugar or a derivative thereof by using activated carbon as a catalyst； and a catalyst composition for use in the reaction for producing 5-HMF from a carbohydrate comprising a hexose as a constituent sugar through a dehydration reaction, the catalyst composition comprising activated carbon.
