Nanowires assembled sub-WO3 urchin-like nanostructures have been fabricated via a solvothermal method. The detailed structure and morphology features were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The results reveal that the individual nanowires are grown along the [001] direction, and assembled together to form an urchin-like nanostructure. Sensing performance of the sub-WO3 was investigated toward alcohol vapor. At room temperature, the sensor devices based on the WO3 (x) exhibit significantly higher sensitivity comparing to that of the stoichiometric WO3. The superior sensing performance of this WO3 x sensor is ascribed to the large specific surface area and abundant oxygen vacancies. The obvious enhancement of the gas sensing property can be very useful for the future design and development of room temperature gas sensors for other volatile organic compounds. (C) 2018 Elsevier B.V. All rights reserved.