The rate constant for the reaction S + SO2 --> SO + SO (1) has been investigated by measuring time profiles of S atoms behind reflected shock waves using two experimental systems: S atoms were provided by the thermal decomposition of COS in the high-temperature range (2020-2800 K) and by excimer laser photolysis of COS in the low-temperature range (T = 1120-1540 K). The results of these experiments yield the rate constant with a non-Arrhenus temperature dependence, k(1) = 10(-39.73)T(8.21) exp(4828.5/T) cm(3) molecules(-1) s(-1), over the extended temperature range (1120-2800 K). By comparing the rate constants with that derived from a conventional transition-state theory based on the potential energy surface calculated by the G2M-(CCl) methodology, a reaction mechanism including a contribution of the singlet state of the reaction intermediate S2O2 is discussed.