To provide a hot melt adhesive agent for waterproofing, which is excellent in coating ability and suitable to adhesion between a urethane elastomer as a waterproofing material and asphalt concrete as a paving material, and also provide a method for waterproofing and an adhered article using the adhesive agent.

In a waterproofing method comprising setting forth a paving material on a floor through a water proofing material, the adhesive agent for fixing the waterproofing material and the paving material to each other comprises a hot melt adhesive agent for water proofing containing (A) a copolymer consisting of (a1) an aromatic vinyl monomer, (a2) an aliphatic or an alicyclic unsaturated hydrocarbon and/or (a3) an alkyl or alkenyl (meth)acrylate as the essential constitutional monomers.