EMI shielding performance is measured by adjusting variable like filler size and foam pore size. Fillers are carbon materials decorated with Ag, and a surface modification didn’t used acid for minimizing damage. Silver is good for EMI shielding material, because of high electro conductivity and permittivity, but it is expensive. Foam and silver decorated on carbon material solve the problem. Decorating Ag on carbon materials makes loading Ag wt% to decrease but vol% to increase. Likewise Foam makes the same effect as decoration. Scanning Electron Microscope(SEM) and Micro-CT show filler network. For Ag decorated carbon materials, use SEM and X-ray photoelectron spectroscopy(XPS). Electromagnetic Interference shielding performance is tested as the samples are 2mm thickness in 1GHz-20GHz.