Bidirectional interdependency between graphene doping level and ferroelectric polarization is demonstrated in graphene/PbZr0.2Ti0.8O3 hybrid structures. The polarization of the PbZr0.2Ti0.8O3 can be effectively switched with graphene electrodes and can in turn alter carrier type and density in the graphene. A complete reversal of the current-voltage hysteresis direction is observed in the graphene when external environmental factors are minimized, converting p-type graphene into n-type with an estimated carrier density change as large as ~10(13) cm(-2). Nonvolatility and reversibility are also demonstrated.