The effects of the initial pH and ionic strength of a solution on the absorption rate, absorption efficiency, and selectivity of NO(2) absorption into magnesium/calcium sulfite slurry were experimentally investigated. A mixed gas containing NO(2) was sparged into a bubble column absorber, and the concentrations of nitrite and nitrate in the absorbing slurry were measured. Nitrite was selectively produced using magnesium/calcium sulfite slurry, which has a pH greater than approximately 5, while both nitrate production and nitrite desorption were suppressed. No effects of the magnesium/calcium sulfite concentration and ionic strength on the absorption rate and absorption efficiency were found in this study. The absorption performances of magnesium/calcium sulfite slurry were the same as those in a sodium sulfite solution.