This article presents the results of an experimental study on the thermal conductivity of the hydrazine hydrate system + concentrations (0.1, 0.15, 0.2, 0.25, 0.3%) of metal oxide nanoparticles (Al2O3, Fe2O3, TiO2 d = 50 nm) in the temperature range 298–348 K at atmospheric pressure. The result of the study showed that the thermal conductivity of the system hydrazine hydrate + nanoparticles of metal oxides, depending on temperature and atmospheric pressure, increases when the nanoparticles of metal oxides change from 0.1 to 0.3%.