A feedback circuit for push-pull inverters aims to improve the existing push-pull inverters that provide input electricity to a discharge lamp at a phase difference of 180 degrees without feedback electricity to regulate frequency signals and cannot effectively control uniform luminance of the discharge lamp. The invention includes a feedback device to get a detection electricity of the driving electricity of the discharge lamp through non-contact coupling induction. The detection electricity is transformed by the feedback device and output to a frequency control unit. The control unit can regulate and output the frequency signal in response to the luminance of the discharge lamp to timely adjust input electricity of a push-pull inverter.