A method of fabricating a pixel structure is provided. A gate electrode is formed on a substrate, and a dielectric layer is formed on the gate electrode. A patterned metal oxide semiconductor layer and a patterned metallic etching stop layer are formed on the dielectric layer above the gate electrode. A first conductive layer is formed to cover the patterned metallic etching stop layer and the dielectric layer. The first conductive layer is patterned by using the patterned metallic etching stop layer as an etching stop layer to form a source and a drain. A second conductive layer is formed to cover the source, the drain and the dielectric layer. The second conductive layer is patterned by using the patterned metallic etching stop layer as an etching stop layer to form a first electrode layer. The patterned metallic etching stop layer exposed between the source and the drain is removed.