In this paper we studied the adsorption and desorption behavior of SO2 by the dead Bacillus licheniformis R08 biomass. The effects of water vapor, temperature and O-2 on the removal of SO2 by the biomass were studied. FTIR and XPS were used to characterize the mechanism of the SO2 adsorption on the biomass. The experimental results showed that water vapor and temperature deeply influenced the adsorption of SO2 by the biomass. However, O-2 cannot oxidize SO2 to SO3 on the biomass. FTIR and XPS results showed that oxygenous and nitrogenous functional groups on the cell walls of biomass may be related to the SO2 adsorption and three sulfur species were formed on the biomass in adsorption process. In the desorption process, weakly adsorbed SO2 could be desorbed by increasing temperature and the biomass can be reused for 10 cycles. (C) 2009 Elsevier Ltd. All rights reserved.