The method for producing an aqueous dispersion containing a complex of poly(3,4-dialkoxythiophene) and a polyanion comprises: a process of polymerizing 3,4-dialkoxythiophene in the presence of a polyanion by using an oxidizing agent in an aqueous solvent, in which polystyrene-sulfonic acid having a specific molecular weight and a sulfonation degree or polystyrenesulfonic acid having another specific sulfonation degree is used as the polyanion, or in which pH of the reaction mixture during the reaction is set to a specific value.