The degradation reaction mechanism of desflurane radical in the presence of NO were investigated using density functional theory. The geometries of all the species were optimized at B3LY10/6-311++G** method. All the energy information are determined using configuration interaction method QCISD(T)/cc-pVTZ. Six connected reactions were found, which are labeled as Reaction 1, 2, 3, 4, 5 and 6 with the Gibbs barriers of 9.37, 13.74, 26.62, 0.99, 19.49 and 120.36 kJ/mol, respectively. The corresponding rate constants were also evaluated. The detailed reaction mechanism were analyzed and the results show that the Reaction 6 is a rate-determining one of all. (C) 2016 Elsevier B.V. All rights reserved.