Experimental results indicated that fulvic acid can significantly promote the volatilization of MnO₂-Hg,Fe₂O₃-Hg and kaolinite-Hg, but suppress that of bentonite-Hg and CaCO₃-Hg. Generally brown humic acid can enhance the volatilization of all the mineral-bound Hg except for Fe₂O₃-Hg. The effect of grey humic acid is the weakest. The influence of humus fractions on the activity of mineral-bound Hg is dependent on the complex capacity and complex stability of humus fractions with Hg, adsorption capacity and adsorption strength of the mineral with Hg as well as the interaction characteristics between humus fractions and minerals.