With more stringent environmental regulations or acts being implemented, the research on developing a desulfurization/denitrification technology with high efficiency and cost performance becomes very urgent. In this paper, TiO2 catalyst with the addition of different promoters and additives were tested in a laboratory scale plasma reactor. Promoters are V2O5 and K2O-V2O5, and additives are H2O and H2O2, respectively. The experimental results indicate that the promoters (V2O5 and K2O-V2O5) are considerably effective in promoting the activity of TiO2 catalyst in the presence of plasma, which causes the SO, oxidation rate to increase. Meanwhile, K2O-V2O5 (K-promoter) is found to be a better promoter than V2O5. Except for promoters, the additives (H2O, H2O2) also have an important impact on SO2 oxidation in the case of simultaneously using plasma and TiO2 catalyst.