In this paper, gas sensing property of a nitrogen doped ZnO was studied. nanofilms of pure and nitrogen-doped ZnO (0.1, 0.2 and 0.3 normality) were prepared on glass substrate by spray pyrolysis technique. These films were fired at 450°C for two hours in air atmosphere. nanobehavior of the films was confirmed by XRD and SEM analysis. Gas sensing behavior of the films was tested in static gas sensing system. Films were exposed to different gases as LPG.NH3, NO2, Ethanol vapour and CO2 at different ppm concentrations and different operating temperatures. Pure ZnO films showed poor sensing behavior. At 150°C, films of N-doped ZnO (0.3 normality) showed good sensing for Ethanol vapours. The gas sensitivity was determined as 86.8% for 200 ppm of Ethanol vapours. When compared with pure ZnO, the nitrogen doped ZnO films possessed more oxygen deficient species. Due to this crystal defects arising from nitrogen doping, the improvement in gas sensing property of ZnO may be argued. Keywords: Spray pyrolysis; ZnO; N; XRD; SEM; LPG