In this study, structural, morphological and optical properties, and gas sensor performance of magnesium oxide (MgO) doped titanium dioxide (TiO2) thin films were investigated in detail. Gas sensor metallic patterns were fabricated on Si substrate using traditional photolithographic technique. MgO doped TiO2 thin films were deposited on formed Pt electrode surface by confocal sputtering (co-sputtering) system as the active layer. Thin film characterizations were realized by using secondary ion mass spectroscopy (SIMS), atomic force microscope (AFM) and UV-Vis Spectrometer (UV-Vis). Gas sensing measurements were performed by gas sensing test system against methane gas at working temperature of 300 degrees C. To evaluate deposition and thermal annealing effects on the sensing performance, sensors were tested under gas. The sensitivity and response/recovery time of gas sensors were measured in 1000 ppm. MgO doped TiO2 based sensor at substrate temperature of 100 degrees C has high sensitivity and short response/recovery time.