A pixel structure and a method of manufacturing a pixel structure are provided. The pixel structure includes an active device, a gate insulation layer, a dielectric insulation layer, a capacitance electrode, a protection layer and a pixel electrode. The active device includes a gate, a semiconductor channel layer, a source and a drain. The dielectric insulation layer covers the semiconductor channel layer. A dielectric index of the dielectric insulation layer is greater than a dielectric index of the gate insulation layer. The capacitance electrode is overlapped with the drain. The capacitance electrode, the drain and the dielectric insulation layer between the two constitute a storage capacitor structure. The protection layer is disposed on the dielectric insulation layer and the capacitance electrode is located between the protection layer and the dielectric insulation layer. The pixel electrode is disposed on the protection layer and connected to the drain of the active device.