A phosphor wheel includes a glass, a first phosphor agent and a first filter. The glass has a first region and the first phosphor agent is coated on the first region for converting a first color light into a second color light. The first filter is disposed next to the first region for filtering at least a portion of the first color light and a first light beam of the second color light, so that a second light beam of the second color light is transmitted through the first filter. The second color light is yellow light, the first phosphor agent is yellow phosphor agent, and the first filter is a red light filter. The present invention achieves the advantages of decreasing the fabricating cost, increasing the brightness of the red light with increasing of driving current and the whole brightness of the illumination system, and improving the image quality.