In the recent research, a novel type of dopant element in the indium based oxide thin film transistor: tungsten was proposed to replace the expensive and rare gallium element for its low price and even higher oxygen bond dissociation energy, which may further improve the device instability and keep the carrier mobility with a low temperature process at the same time. Therefore, the tungsten doped channel material is more suitable for the flexible device than other transparent amorphous oxide semiconductors. In this work, the devices with tungsten doped channel material were manufactured on a polyimide substrate, which exhibit an acceptable electrical performance and reliability characteristic without a high temperature treatment. In addition, a bending test was also carried out to check the stability for the flexible device.