A projector includes a light source module, a light valve, and a projection lens. The light source module is adapted to provide an illumination light beam and includes a base having first and second side surfaces, first and second color light-emitting units respectively disposed on the first and second side surfaces, and first and second heat dissipation structures respectively connected to the first and second color light-emitting units. The first and second heat dissipation structures are separated from each other and define an accommodation space together. The light valve is located on a transmission path of the illumination light beam and adapted to convert the illumination light beam into an image light beam. The projection lens is located on a transmission path of the image light beam and adapted to project the image light beam.