Department of Chemical Sciences, Tezpur University Tezpur, Napaam-784 028, Assam, India E-mail : ramesh@tezu.ernet.in, nkgour1@tezu.ernet.in Department of Chemistry, Indian Institute of Technology, Guwahati-781 039, Assam, India Department of Physics, Girijananda Chowdhury Institute of Management and Technology, Guwahati-781 017, Assam, India Manuscript received 06 December 2017, accepted 20 December 2017 A detailed density functional studies of the reaction of n-butyl nitrate initiated by OH radical as well as atmospheric life-time of the titled molecule have been carried out by using hybrid functional M06-2X method along with 6-311+G(d,p) basis set. We obtain the possible H-abstraction channels of the reaction of n-butyl nitrate with OH radical on the potential energy surface along with the thermochemistry associated with it. The overall rate constant as well as individual rate constants for four plausible pathways of the re- action are calculated using the canonical transition state theory (CTST) at 298 K and 1 atm. Kinetically, the path which involves the abstraction of H atom from the -OCH2 site of CH3CH2CH2CH2ONO2 is found to be the dominant one and the calculated overall rate constant is 3.63×10–12 cm3 mol–1 s–1, which is in good agreement with the experimentally value, 1.66×10–12 cm3 mol–1 s–1. The reported kinetic and thermo-chemical results in this work would be helpful for further degradation and decomposition pathways of the generated radical into the atmosphere.