The results of development and testing of the experimental method for determining the thermal conductivity coefficient of nanofluids are presented in this work. The measuring of thermal conductivity coefficients of the water and the ethyleneglycol were carried out for testing developed technique. The thermal conductivity coefficients measures of the ethyleneglycol-based Al₂O₃ and CuO nanofluid at the room temperature were carried out. Satisfactory coincidence of the thermal conductivity coefficients measured by authors of this article and by other authors was obtained.