This invention provides a driving circuit for simultaneously driving three-color bistable liquid crystals, which employs a voltage-shift circuit to provide different-color bistable liquid crystals with respective level-shift voltages. A grey-scale voltage is respectively added to the respective level-shift voltages. By this invention, the whole grey-scale voltages are capable of falling in the voltage ranges for displaying grey scales for the different-color bistable liquid crystals. The grey-scale display can be optimized.