R adon, a carcinogenic substance generated from soil or building materials, have tobe fundamentally blocked from entering indoors. In this study, ethylene vinyl acetate (EVA)/siliconeemulsions with excellent mechanical and thermal properties and effective blocking of radon gas wereprepared by using radiation technology. As the electron-beam irradiation does increased, a partiallycrosslinked structure was formed in EVA molecular chain, increasing tensile properties and adhesivestrength. The EVA/silicone film showed excellent thermal stability without deformation. In addition, thenon-irradiated EVA/silicone film showed a radon blocking rate of about a 75%, while the EVA/silicone filmirradiated with 3 and 5 kGy showed an excellent radon blocking rate of over 90% due to the formation ofcrosslinked structure in the EVA molecular chain. These results indicated that the radiation technologycan effectively block radon by forming a partially crosslinked structure of EVA/silicone emulsion toimprove tensile property, adhesive strength, and deformation stability.