We studied characteristic of carbon-doped indium-tungsten-oxide (In1-xWxOC) thin film transistors (TFTs) with SiO2 gate insulator.The In1-xWxOC films, were fabricated by co-sputtering method with WC and In2O3 targets, had an amorphous structure and maintained W-C bond even after annealing at 300°C. The saturation field-effect mobility, on/off current ratio and subthreshold swing values of the In0.96W0.04OC TFT were 5.6 cm2/Vs, 1.0 × 109 and 0.52 V/decade, respectively. To effect of doped carbon in In1-xWxOC channel on reliability of transistor properties, we compared the turn on voltage shift (ΔVon) behavior between the In0.96W0.04OC and In0.98W0.02O TFTs under positive gate bias stress (PBS) and negative gate bias stress (NBS). The ΔVon of the In0.96W0.04OC TFT was always smaller than that of In0.98W0.02O TFT under PBS. Moreover, it is clear that the ΔVon (∼ 0 V) of In0.96W0.04OC TFT was improved significantly compared to that (-0.5 V) of In0.98W0.02O TFT under the NBS of 5000 s. We concluded that the In1-xWxOC film is one of the promising candidates as InOx-based metal oxide semiconductor channel material.