In this study, the efficiency of ultraviolet photochemical reactor using ultraviolet radiation, which was induced by a vacuum ultraviolet lamp, was examined for the removal of SO2 from flue gas. Reactor volume was 72L, and in the reactor, baffles were installed for effective flow control of SO2 removal. Using SO2 concentration range was 1000 ~ 3000 ppm. (NH4)2SO4 was obtained as a by-product. Under streaming NH3/SO2 2:1 molar ratio was optimum in SO2 removal.