The transport properties and adsorption characteristics of H2S and NH3 on CoO nanowire is studied using density functional theory combined with non-equilibrium Green's function. The adsorption properties of H2S and NH3 on CoO nanowire are investigated in terms of density of states, transmission coefficient and V-I characteristics. The adsorption of H2S and NH3 on CoO nanowire is confirmed with more peak maximums in the transmission spectrum. The present result shows that CoO nanowire molecular device is more selective towards H2S than NH3. (C) 2015 Elsevier B.V. All rights reserved.