The deactivation of impregnated Fe-K/alumina catalyst during CO2 hydrogenation to hydrocarbons has been studied. After the catalyst had been employed for 850 h, a long-term (850 h) reaction test led to 37% reduction in the hydrocarbon synthesis activity. With the deactivated catalyst, solvent extraction, reduction and oxidation-reduction treatments have been examined for the catalyst regeneration. The characterizations have been carried out by means of chemisorption, BET measurement, elemental analysis and X-ray diffraction with the fresh catalyst, the deactivated catalyst and post-treated catalysts. From the results, it can be deduced that the catalyst deactivation is mainly caused by the carbonaceous deposits. The deactivated catalyst has been successfully regenerated by the oxidation-reduction treatment.