The article presents the results of a study of a composite material based on epoxy-diano resins containing a nanocarbon dispersed filler. The effect of small soot and carbon nanotube inclusions on the change in the mechanical characteristics of the cured epoxy resin ED-20 depending on the degree of filling was investigated. Measurements of the ultimate strength, effective modulus  and maximum deformation before specimen fracture were performed during tensile tests, compression, and bending. The study of the mechanical properties of the specimens was carried out on an AG-X Autograph Series Shimadzu universal testing machine under typical conditions, i.e. room temperature. Found a significant increase in the ultimate strength and plastic deformation of the cured resin with the introduction of the addition of carbon black and nanotubes. The change in the effective modulus during the deformation up to the destruction of the material was determined. Two stages of deformation with a different character of modulus change are revealed: its monotonous decrease and its almost constant value. On this basis, it was concluded that the process of deforming epoxy composites with a consistent change in the deformation mechanisms is complex.