Pure and Au nanoparticles loaded WO₃ nanoflowers are synthesized by the hydrothermal method.The structures and morphologies of the as-prepared products are characterized by X-ray diffraction (XRD),scanning electron microswcope (SEM), and transmission electron microscope (TEM). The gas sensing performance of the Au/WO₃ sensor to xylene is investigated. The Au content and the operating temperature are first optimized. It is found that WO₃ with 0.4 μL Au nanoparticles shows the highest sensitivity at an operating temperature of 250 ℃. Compared with pure WO₃, Au(0.4)/WO₃ possesses fast response/recovery speed and high target gas selectivity. Its sensitivity to 100 ppm xylene is 29.5. Meanwhile, the practical detection limitation is as low as 0.5 ppm. Finally, the mechanism of Au/WO₃ gas sensing is also proposed and discussed. Au nanoparticles loaded WO₃ nanoflowers are considered to be a promising sensing material for detecting xylene pollutants.