Gas sensor based on point contact tungsten trioxide (WO3) was prepared by in-situ induction-heating thermal oxidation of tungsten filaments. X-ray diffractometry (XRD) and field emission scanning electron microscopy (FESEM) were employed to analyze the phase and the morphology of the fabricated thin films. The results showed that the WO3 films exhibited a monoclinic phase and were composed of hierarchical micro and nano crystals. The NO2 (1-8 ppm) sensing properties of the point contact sensors based on Pure and Au-sputtering doped (2.5 at%) WO3 films were investigated. The results showed that the gas sensing properties of the Au (2.5 at%) doped WO3 sensors were superior to those of the undoped. The obtained point contact WO3 sensor exhibited the maximum NO2 gas response at 100°C.