Non-fully oxidized tungsten oxide（WO_（3-x）） nanostructures with controllable morphology were fabricated by adjusting the gas pressure in chemical vapor deposition.The comparative field emission（FE） measurements showed that the obtained W_（18）O_（49） nanowires have excellent FE property.The turn-on field was 7.1 V/μm for 10μA/cm^2 and the observed highest current density was 4.05 mA/cm^2 at a field of 17.2 V/μm.Good electron emission reproducibility was also observed during thermal evaporation and desorption testing.
