To improve the heat insulating property of plastic films, SiO2 nanoparticles as inorganic insulating filler were prepared from sodium metasilicate by emulsion method in reverse micelle. MgO, Al2O3 and CaO nanoparticles were also prepared. Surface modifications of synthesized heat insulating nanoparticles were accomplished with MPS ( mercaptopropyl trimethoxysilane) coating to maximize homogeneous distribution and compatibility between obtained heat insulating nanoparticles and EVA ( ethylene vinylacetate). Finally heat insulating films were prepared with MPS coated-heat insulating nanoparticles at the ratio of 2 wt% and EVA. The insulating capacity was tested by IR spectroscopy and light transmission was observed by UV-vis spectroscopy. The mechanical properties such as tensile strength, elongation, impact strength, tear strength, clarity and haze were also studied.