A method for manufacturing a pixel structure includes providing a substrate having an active device thereon and forming a dielectric layer covering the active device. Then, an uneven first photoresist layer having an opening is formed over the active device. After an etching process is implemented to form a contact hole in the dielectric layer through said opening, a thickness of the first photoresist layer is reduced so as to expose a portion of the dielectric layer. A transparent conductive layer covering the exposed dielectric layer and the remained first photoresist layer is formed and electrically connected to the active device via the contact hole. Thereafter, the transparent conductive layer on the remained first photoresist layer is removed, while the transparent conductive layer on the exposed dielectric layer forms a pixel electrode. Then, the remained first photoresist layer is removed. With fewer photomasks, the method reduces the manufacturing costs.