A pixel structure disposed on a substrate including a thin film transistor (TFT), a bottom capacitor electrode, a dielectric layer, an upper capacitor electrode, a passivation layer, and a pixel electrode is provided. The TFT having a source/drain and the bottom capacitor electrode are disposed on the substrate. The dielectric layer is disposed on the bottom capacitor electrode. The upper capacitor electrode has a semiconductor layer, a barrier layer, and a metal layer. The semiconductor layer is disposed on the dielectric layer above the bottom capacitor electrode. The barrier layer is disposed on the semiconductor layer. The metal layer whose material includes copper, a copper alloy, or a combination thereof is disposed on the barrier layer. The passivation layer covers the TFT and the upper capacitor electrode and has a first opening exposing the source/drain. The pixel electrode is electrically connected to the TFT through the first opening.