The present invention refers to a system, composed by mechanical and electronic components and by a resident software inherent to the system. The system for the mean of thermal properties of fluids is destinated to the measure of thermal properties such as diffusivity and effusivity, and from those values, to obtain the conductivity and the volume thermal capacity of flowing media. Besides the use for the direct measure of thermal properties, the referred system has application in the verification of the quality or of adulterations in fuels (octane and no conformity), fuel oils and lubricants, perfumes, foods, drunk, and working as humidity met gases. In these cases the essential feature is the correlation of the measure of thermal property and the quality parameter of the substance analyzed. The present invention can used in industries and laboratories.