For researching the co-adsorption behavior of SO2, NO and CO2 in flue gas, the adsorption characteristics of pure component on activated carbon fiber (ACF) at temperatures ranging from 323.15 K to 363.15 K have been experimentally measured by a volumetric apparatus. The equilibrium data were analyzed by the Langmuir and Freundlich model, which revealed that Freundlich model was more suitable to describe the three gases adsorption than Langmuir model. The Henry's Constant was investigated based on the adsorption isotherms. The results showed that adsorption affinity follows the order SO2 > NO > CO2 on ACF. Thermodynamic functions integral Gibbs' free energy, enthalpy and entropy were calculated to characterize adsorption behavior. Finally, The Extended Langmuir (EL) Model was used to predicted multicomponent competed adsorption. We compared the experimental data both for the individual adsorption and for the mixture adsorption in our research. This work can provide helpful information to understanding the removal SO2, NO and CO2 via simultaneous adsorption on ACF in further studies. (C) 2012 Elsevier B.V. All rights reserved.