Abstract: Planar-gate FED， whose cathode and gate are parallelly distributed in the same plane. There is vacuum between the cathode and the gate which is also called no mediator FED.Being different from normal-gate and undergate FED, which applies high voltage to the anode, scanning signal to the gate, and data to the cathode. This paper proposes a no mediator FED driving system. It applies scan signal to the anode, data to the gate, and negative voltage to the cathode. Data acquisition and caching，the grayshade column driving and the row scanning circuit are also adopted in the system. A no mediator FED prototype that can display word and image has been worked out.

Key words: no mediator, FED, driving system