Abstract: The chemical reaction in the process of fluoride removal with limestonegypsum from flue gas was described. Based on the twofilm theory, the kinetic model of CaCO3HF reaction was established and analyzed. The effects of reaction temperature, reaction time, HF vaporphase pressure and ratio of Ca/F molar ratio on the fluoride removal reaction were explored. The results show that the conversion of a CaCO3 particle and the fluoride removal efficiency increase as the reaction temperature, the reaction time and HF vaporphase pressure are raised. The molar ratio of Ca/F molar ratio significantly affects the fluoride removal efficiency. It is suggested that twofilm theory model can be used to describe the dynamical behavior of fluoride removal reaction with wet limestone/gypsum. The investigation results are of important significance for studying the mechanisms of gaseous fluoride removal by the typical wet FGD techniques and developing the uniform control technology of coalfired pollutants.