Abstract: The adsorbents of synthetic graphite which can adsorb both long chain nparaffins and polycyclic aromatic hydrocarbons were prepared by the use of high pressure homogenizer. By the aid of gas chromatography and UV spectrometry, the adsorption ability of adsorbent has been studied and the equilibrium equation of isothermal adsorption has been deduced. The equilibrium constant K (1400 to 4025) and the standard free energy of adsorption (-17 to-26kJ/mol) have been calculated. It has been proved that the synthetic graphite adsorbent has ability of double adsorption. B esides, the factors which affect adsorption ability i. e., adsorption time, temperature, ratio of solid to liquid, size and dispersion degree have been discussed. The result shows that the size and dispersion degree are primary factors which affect the adsorption ability of graphite.