Commercial silica gel, type Si-60, was coated by pyrolytic coke during different times. The porous structure of obtained carbon-silica adsorbents (carbosils) was analysed on the basis of nitrogen adsorption-desorption measurements at 77,5 K. The equation of Dubinin and Izotova and the Horvath-Kawazoe adsorption model were used for determining the micropore structural parameters. The fractal analysis was performed on the basis of the Frenkel, Halsey and Hill theory and analysis of adsorption data. The new correlation between fractal dimension and average pore size associated with the power law was found. The fractility factor, defined as a measure of a distance from a completely smooth surface, was used for analysis in influence of fractality on the changes of porous structure.