Abstract: In order to study effect of viscose activated carbon fibers (ACFs) modified with wet oxidant, the influence of textural characteristics and surface chemistry of ACFs modified with wet oxidant of H₂O₂ in the adsorption of toluene were studied under laboratory tests. The experimental results indicated that compared with the original sample, the textural characteristics such as micro volumeof ACFs modified with different concentrations of H₂O₂ advanced and favoredthetoluene adsorption. ACFs modified with different concentrations were prepared to have similar textural characteristics but different surface chemistry. It was observed that with the increase of the impregnated concentration of H₂O₂, the amount of CO-evolving groups of ACFs was reduced gradually and favored the tolueneadsorption, however, the amount of CO₂-evolving groups was increased gradually and was detrimental for toluene adsorption. In general, the total number of oxygen surface groups (i.e., both CO and CO₂-type groups) was high, but the toluene adsorption capacity was low. The results confirmed that π-π dispersion force between ACFs and toluene molecule was the key factor for toluene adsorption on ACFs modified with wet oxidant.