The monolithic foamed gold was synthesized by seed-mediated growth with polystyrene (PS) template and casting procedure and heat treatment. The results indicate that the PS could be coated by gold colloid with average grain size of 4.6 nm which was made in toluene by the electrostatic effect. The deposited gold with thickness of 70-90 nm and grain size of 30-60 nm were obtained by electroless plating. It can be self-supported after the template removing. The casting procedure is analogous to slip-casting of ceramic that results in randomly-packed PS/Au spheres with void spaces between individual particles. The columniform foamed gold with hollow spheres of 8-9 μm, diameter of 4 mm, density of 1.5 g/cm3, and porosity of 92% was obtained after heat treatment.