To provide an aqueous dispersion which is excellent in storage stability and weather resistance and gives a film excellent in adhesive properties or adhesion to various substrates as well as excellent in water resistance and weather resistance.

The aqueous dispersion comprises a block copolymer comprising an aromatic vinyl polymer block A bonded via a sulfur atom to a polymer block B comprising 2-100 mole% of a vinyl monomer unit bearing at least one functional group selected from the group consisting of a carboxyl group, an acid anhydride group, a hydroxyl group, a sulfonic group, an amino group and an amide group and 98-0 mole% of a unit of another vinyl monomer copolymerizable with the vinyl monomer.