The paper examines thermal properties of materials. The transient pulse method was used for specific heat, thermal diffusivity and thermal conductivity determination. Porous MgO was synthesis by heating pellets at 1100 °C for 1h. The resultant porous MgO was then immersed in an 10mol/L aluminium nitrate solution, dried, and reheated at 1300 ºC for 2h to convert it to spinel. The evaluation was performed with the help of mathematical apparatus used for study of fractal structures properties. The method results from generalized relations that were designed for study of physical properties of fractal structures. As it is shown these relations are in a good agreement with the equations used for the description of time responses of temperature for the pulse input of supplied heat.