Fabric filters are involved in most semi-dry flue gas desulfurization process and represent ability of SO2 removal. SO2 removal efficiency in fabric filter after a semi-dry scrubber is investigated. Experimental results showed that SO2 inlet concentration has little effect on SO2 removal efficiency, SO2 removal efficiency increases as flue gas inlet temperature increases and relative humidity affects SO2 removal efficiency significantly. The kinetic model based on shrinking core theory has been presented. It is found that, in the beginning, when calcium hydroxide conversion ratio is less than 0.3, SO2 removal process is mainly controlled by chemical reaction (Model-2); and when calcium hydroxide conversion ratio is greater than 0.3, SO2 diffusion through product layer is rate limiting (Model-3). The experimental results in fabric filter are successfully correlated by Model-3. (C) 2008 Published by Elsevier B.V.