A pixel circuit of low power consumption is provided, which includes a first transistor for providing a driving current, a light emitting element, a light emitting control circuit, a reset circuit, a writing circuit, and a storage capacitor. The light emitting control circuit is coupled between the first transistor and the light emitting element, and is for selectively conducting the driving current to the light emitting element. The reset circuit is for providing a first reference voltage to the light emitting element by a first frequency. The storage capacitor is coupled between the writing circuit and the first transistor. The writing circuit is for providing, by a second frequency different from the first frequency, a data voltage and a second reference voltage to the storage capacitor and the first transistor, respectively. The storage capacitor is for storing a first voltage for compensating a threshold voltage of the first transistor.