The effect of nano-fillers (carbon carbon nanotubes) on thermophysical properties of epoxy composites is investigated. The curve showing the dependence between the heat resistance of epoxy composite and the content of nanoparticles demonstrates the optimal content of carbon carbon nanotubes, indicating the improved performance characteristics of the material with the above content of carbon carbon nanotubes. To analyze the processes of structure formation and the behavior of composites under the influence of a thermal field, the thermal coefficient of linear expansion of materials is investigated. It is established that the thermal linear expansion coefficient of materials increases with an increase in temperature within different temperature areas under study. Additionally, the thermogravimetric (TGA) and differential thermal (DTA) analysis of the materials were conducted for the investigation of nanocomposites under elevated temperatures. The maximum values of endothermic and exothermic effects in composites depending on their filling are found.