The aqueous dispersion of the present invention is produced by incorporating a block copolymer (II) into an aqueous dispersion (I) of a block copolymer (I) in an aqueous solution containing a basic compound. The block copolymer (I) is composed of a polymer block (A) mainly constituted by a constitutional unit derived from an olefin monomer and a polymer block (B) constituted by a constitutional unit derived from a vinyl monomer (b1) having a carboxyl group, a carboxylic anhydride group or a sulfonic group and a constitutional unit derived from another vinyl monomer (b2) copolymerizable with the vinyl monomer (b1). The content of the basic component is 0.05 equiv or more of the carboxyl group, carboxylic anhydride group or sulfonic group, each contained in the unit derived from the vinyl monomer (b1). The block copolymer (II) is composed of a polymer block (X) mainly constituted by a constitutional unit derived from an aromatic vinyl monomer and a polymer block (Y) constituted by a constitutional unit derived from a conjugated diene monomer. The aqueous dispersion provides a flexible coating film which is excellent in bonding and adhesion properties to various substrates.