A projector includes a light source, a light integration rod, a light valve, and a projection lens. The light source provides an illumination beam. The light integration rod has a light incidence end and a light emission end opposite to each other. Through the light incidence and emission ends, the illumination beam is emitted into and out from the light integration rod, respectively. Each of the light incidence end and the emission end is in a rectangular shape. The light incidence end has a first long edge and a first short edge. The light emission end has a second long edge paralleling to the first short edge and a second short edge paralleling to the first long edge. The light valve converts the illumination beam into an image beam. The projection lens is disposed on a transmission path of the image beam. A light integration rod is also provided.