The simultaneous absorption of NO and SO2 by Fe(II)EDTA combined with Na2SO3 solution was studied by cyclic voltammetry and Raman spectroscopy for the purpose of investigation on the reaction products and reaction mechanism. It was found that the high efficiency (more than 60%) period of NO absorption with the presence of SO was 1.59 times longer than that without SO2. At the same time, the existence of SO2 increased the absorption capability of NO by 36.65% within 500 min, compared with NO absorption by Fe(II)EDTA combined with Na2SO3 solution. The reason may be explained that part of NO had been reduced by SO, before entering into Fe(II)EDTA solution combined with Na2SO3. The addition of Na2SO3 changed pH value of the solution and provided SO32- which realized the regeneration of Fe(II)EDTA absorption solution. The main reactions of the system included the reductions of Fe(II)EDTA(NO), Fe(III)EDTA and NO absorption. The majority consumed SO32- were converted (2-) into SO42-. (c) 2007 Elsevier B.V. All rights reserved.