The reactions of nitrogen dioxide (NO2) with dimethyl ether (CH3OCH3) and 1,2-ethanediol((CH2OH)2) were characterized at a reliable computational level with large basis sets. The results showed that the channel of hydrogen abstraction from -CH3 group was predominant for the CH3OCH3 + NO2 reaction and the channel of hydrogen abstraction from –CH2 group was predominant for the (CH2OH)2 + NO2 reaction. The reaction rate coefficients were calculated at the canonical variational transition state theory (CVT) with the small curvature tunneling (SCT) correction. The effects of reactant complexes on barrier heights and tunneling factors were considered.