To explore the novel application of boron nitride nanotube (BNNT), we have investigated the structural, magnetic and electronic properties of CO and NO molecules adsorption on transition metals (TM = V, Cr, Mn, Fe, Co or Ni) doped (8,0) BNNT using first-principle calculations. The combining processes of all gas adsorption on TM-doped BNNT are exothermic, accompanying with larger formation energies and charges transfer showing that both CO and NO molecules present strong chemical interaction with the TM-doped BNNT, and the adsorption of NO is more stable than that of CO. The presence of CO molecule almost does not change the magnetic properties of the TM-BNNT systems. But the adsorption of NO gas on different sites of different TM doped BNNT has different magnetic moment. The adsorption of CO and NO molecules on TM-doped BNNTs leads to different electronic structure properties of BNNTs. Therefore, the TM-doped BNNT can be used as CO and NO gas sensor manufacturing raw materials, and it may be a potential material for nanodevice applications. (C) 2012 Elsevier B.V. All rights reserved.