In the data write phase T2, the scan signal Scan at a low level controls the second switch transistor M2 and the fourth switch transistor M4 to be turned on. The second switch transistor M2 which is turned on provides the first terminal of the storage capacitor Cst with the data signal Vdata, so that voltage at the first terminal of the storage capacitor Cst is voltage Vdata of the data signal Vdata. The fourth switch transistor M4 is turned on so that the control electrode of the driver transistor M0 is communicated with the second electrode thereof to form a connected diode, so that the storage capacitor Cst is charged with the high-voltage signal VDD at the voltage Vdd(1) through the driver transistor M0 until voltage at the control electrode of the driver transistor M0 becomes Vdd(1)+Vth, where Vth is threshold voltage of the driver transistor M0.