The conductivity in the dark exhibited a pronounced minimum and the photosensitivity a maximum at an annealing temperature of 300 degree C. The electrophotographic properties of PbO with binder layers revealed that the acceptance potential increased and the dark discharge rate decreased with the increase of annealing temperature. The photodischarge rate at constant intensity also increased with annealing. These and other findings are explained on the basis of barrier layer theory for PbS-type photoconductors.