Thin film transistors (TFTs) are used as switching components in pixels, and together with the storage capacitors, form the driving circuit for electronic paper (E-paper) displays. In this paper, we classify the flexible TFTs according to their active layer: organic thin film transistor (OTFT), amorphous silicon (a-Si) TFT, metal oxide thin film transistor (MOTFT). Their research progress in flexible E-paper displays is presented, focusing on the flexibility, electrical properties and stability of the devices. Finally, the comparative analysis suggests that MOTFT is expected to be the best candidate to drive the next generation of flexible E-paper displays by virtue of the excellent electrical properties, high optical transparency and relatively low process temperature.