In the recent years, modern materials have been needed that will have a lasting impact in modern applications. The need for radiation therapy as an important means of modifying nanoscale structures in the manufacture of high performance polymer compounds has important advantages. The aim of this research is to measure the thermal conductivity for epoxy resin as a base material, Nano ceramic powder (SiC) with particle size (64.85nm), and nano Graphite powder with particle size (87.85 nm) are used as a reinforcement materials in composites preparating in different weight fractures (2%, 4%, 6%), while the Hybrid (SiC-Graphit) model are prepared by another weight fractures of (SiC and Graphite), Hand-casting method was used in preparation the research samples. The thermal conductivity tests were measured for all weight fractures in normal conditions (before irradiation). we find the values of thermal conductivity is increased with the increase of weight fractures because of the presence of the reinforcement material, including high thermal conductivity graphite compared to silicon. Tests of the thermal conductivity are measured after irradiation of Gamma rays emitted from the CO60 with energy rate of 1.33MeV and different irradiation doses (6,8,10)KGy. The results show an increase in the thermal conductivity values after the irradiation compared with the results of thermal conductivity in normal conditions. It is worth noting that an atomic force microscope (AFM) has been used to measure the particle size of nanomaterials.