The effects of radiation on tungsten doped indium oxide (IWO) thin-film transistors (TFTs) have been well investigated in this Letter. In order to achieve high stability and excellent electrical performance simultaneously even in high ionizing radiation damage ambient, different concentrations of tungsten dopant have been introduced for the TFT device fabrication. It is interesting that the high energy ionizing radiation may significantly increase the conductivity and influence the total concentration of oxygen vacancy in the transparent amorphous oxide semiconductor material, which may be completely different from the traditional radiation damage effect for silicon based CMOS devices. However, that abnormal phenomenon will be effectively suppressed by the powerful carrier suppressor, tungsten, which may have a high oxygen bond dissociation energy. Therefore, IWO devices with a 4% tungsten oxide dopant might be the optimized result even after high dosage ionizing radiation exposure. Hence, it may provide a promising radiation hardness approach to improve both the electrical characteristics and reliability for next generation displays, which can be used in the control system of nuclear power generation or space technology.