A light source apparatus includes a light guide plate, a number of optical fibers, at least two first light emitting diodes, and at least two second LEDs. Each fiber has a light exiting surface facing the light guide and at least two light entrances at both ends of the fiber. The second LEDs are located on both sides of the light guide plate. Light generated by the first LEDs has a wavelength longer than that generated by the second LEDs. The light generated from the first LEDs enters the light guide plate after travelling through the optical fiber to mix with the light generated from the second LEDs to provide a good color rendering property of the light generated by the light source.