A pixel circuit includes an organic light emitting element, a switching transistor configured to be turned on or off in response to a scan signal, a storage capacitor configured to store a data signal applied through a data line when the switching transistor is turned on, a driving transistor configured to allow a driving current corresponding to the data signal stored in the storage capacitor to flow into the organic light emitting element, and an emission control transistor implemented by an oxide thin film transistor, connected in series to the organic light emitting element and the driving transistor between a high power voltage and a low power voltage, and configured to be turned on or off in response to an emission control signal. The pixel circuit performs a back-biasing operation that compensates for a change in a threshold voltage of the emission control transistor by applying a back-biasing voltage to the emission control transistor.