A method for fabricating a pixel structure is provided. First, a gate, a scan line, and a first terminal are formed on a substrate. A gate insulating layer is formed over the substrate to cover the gate, the scan line, and the first terminal. After defining the semiconductor layer, the gate insulating layer is patterned to exposure the first terminal. A transparent conductive layer is formed over the substrate and a patterned photoresist layer is formed on the transparent conductive layer. The transparent conductive layer is patterned using the patterned photoresist layer as a mask, so as to define a source, a drain, a data line, a pixel electrode, a second terminal, and a contact pad. Because only four photomasks are used to implement the above method for fabricating the pixel structure, the cost of manufacturing can be reduced.