Abstarct: mextal oxide semiconductor-baxsed gas sensors are among the most widely used technologies for gas detection and measurement. Due to their unique properties and commercialization potential, mextal oxide semiconductors play a key role in detecting methane gas (CH4). This dissertation investigates and develops methane gas sensors baxsed on vanadium oxides. In this research, VOx nanostructures were synthesized using the sputtering-secondary oxidation method. Their gas sensing properties toward methane demonstrated the ability to detect methane at room temperature without the need for an activation energy source, with an extremely fast response and recovery time (2 and 3 seconds, respectively). Moreover, selectivity evaluation revealed that this sample exhibited high selectivity against interfering gases, including acetone and carbon monoxide. Subsequently, VO2 nanostructures were synthesized using the hydrothermal method, and the gas sensing performance of the resulting sensor was evaluated. The sensor exhibited weak response to methane at room temperature. However, when the operating temperature was increased to 50°C, the sensor’s response to various methane concentrations improved significantly, with a minimum detectable concentration of 100 ppm. This sample also demonstrated remarkable selectivity toward methane over other gases. Finally, V2O5 nanoribbons were synthesized via the hydrothermal method, and their gas sensing properties were examined at room temperature and at 50°C. At room temperature, the sensor did not exhibit an acceptable response, but upon increasing the operating temperature, a significant enhancement in response and a lower detection limit of 200 ppm were observed. Additionally, the transition of the semiconductor type from n-type to p-type when increasing the temperature from room temperature to 50°C had a noticeable impact on the sensing properties of this sample.