The potential energy surfaces for the OH + divinyl sulfoxide reaction in the presence of O-2/NO are theoretically characterized at the CCSD(T)/6-311+G(d,p)//BH&HLYP/6-311++G(d,p)+ZPE level of theory. Various possible pathways including the direct hydrogen abstraction channels and the addition-elimination channels are considered. The calculations show that the exclusive feasible entrance channel is the formation of adduct CH2(OH)CHS(O)CH=CH2 (IM1) in the initial reaction pathways. In the atmosphere, the newly formed adduct IM1 can further react with O-2/NO to form the dominant products HCHO + C(O)HS(O)CH=CH2 (P9). The calculated results confirm the experimental studies. (C) 2012 Elsevier B.V. All rights reserved.