A phosphor wheel includes a substrate, at least a phosphor agent and a plurality of vortex generators. The substrate has a first region and a second region. The second region has a plurality of openings. The phosphor agent is disposed on the first region for converting the wavelength of waveband light. Each vortex generator includes at least a guide vane. Each guide vane is disposed on the second region, and the projection, which is on the second region, of each guide vane is corresponded to one of the openings, such that a vortex is generated during a rotation of the substrate. Therefore, the efficiency of heat exchange is enhanced, the temperature of light spot is reduced, and further the output efficiency of light of the phosphor agent is increased.