The rate constants of reactions between the SO4·- radical and some common anions in atmospheric aqueous droplets e.g. Cl-,NO3-, HSO3- and HCO3- were determined using the laser flash photolysis technique. Absorption spectra of SO4·- and the product radicals were also reported. The chloride ion was evaluated among all the anions to be the most efficient scavenger of SO4·- . The results may supply useful information for a better understanding of the vigorous radical-initiated reactions in atmospheric aqueous droplets such as clouds, rains or fogs.