To provide an emulsion for foamable materials which has ethylene and vinyl acetate as the essential components, extremely reduces a formaldehyde content and discoloration of the emulsion, and simultaneously excels in blocking resistance against vinyl chloride resin products and an expansion ratio, and an emulsion composition for foamable materials.

The emulsion for foamable materials is obtained by polymerizing a monomer mixture having ethylene and vinyl acetate as the essential components with the use of at least one compound selected from formamidinesulfinic acid, thiourea dioxide, and a derivative thereof as the reducing agent. Further, by rendering the ethylene content in the ethylene-vinyl acetate copolymer resin in the range of 3 to 14 mass%, the emulsion excels in blocking resistance against a vinyl chloride resin product such as a sofa and an electric cord in a room, and furthermore by rendering the toluene insolubles ≤30 mass%, the emulsion excels in foaming properties, particularly the expansion ratio.