A method of fabricating a thin film transistor (TFT) includes first providing a strip-shaped silicon island which is a thin film region with a predetermined long side and short side. Next, the strip-shaped silicon island is subject to an ion implantation to form a first ion doping region and a second ion doping region. The first and second ion doping regions, respectively used as the source and the drain of the TFT, are located at two sides along the long side of the island and substantially perpendicular to the gate. A gate is formed over the strip-shaped silicon island and the first and second ion doping regions, wherein the gate is substantially parallel to the direction of the short side.