A pixel circuit comprises a driving transistor, an electroluminescent unit, a pre-write unit, and a write unit. The electroluminescent unit is controlled by the driving transistor to illuminate in a drive period. The write unit is enabled in a write period recording a data voltage relating to an initial threshold voltage of the electroluminescent unit in first storage element. The pre-write unit is enabled in a pre-write period recording a threshold voltage of the driving transistor and the electroluminescent unit in second storage element. The threshold voltage and the data voltage, stored in the first and the second storage units, are supplied as a gate-source voltage of the driving transistor, so as to provide a compensated drive voltage, capable of compensating the variation of the threshold voltages of the driving transistor and the electroluminescent unit, driving the electroluminescent unit.