Abstract: In order to improve the responses and recovery speeds of NiO gas sensing materials, Zn-doped NiO nanowires are prepared via reduction of Magnetic field induced hydrazine combined with subsequent high temperature oxidation, sensitivity to ammonia of sensors is researched based on Zinc-doped Nickel oxide nanowires. Results obtained from the research show that all the peaks of XRD have a slight shift toward lower angles (0.2°~0.4°) and the interplanar distance has a slight increase (0.01~0.02 nm) with increasing Zn dopant concentration from 2 to 5mol%, which is assigned to the successful incorporation of zinc ions in the NiO host structure. The gas sensor based on NiO nanowires with 2~5mol% of Zn doping has 6~8 times faster response speed, and 108~120 times faster recovery speed than pure NiO sensor. Meanwhile, the doped NiO sensor has excellent stability and selectivity toward NH₃ gas over other organic gases.