A CaGa₂S₄-CaS composite doped with Eu²⁺ has been prepared by cooling the corresponding melt of the composition of 65CaS•35Ga₂S₃ containing 1 mol% EuS in order to obtain an efficient bicolor phosphor applicable to white light emitting diode. Efficient green and red fluorescence were simultaneously observed at around 555 and 645 nm, respectively, under 476 nm excitation. Especially, the red emission was about three times as intense as a simple mixture of CaGa₂S₄: Eu²⁺ and CaS: Eu²⁺ powders with the same composition. It was also found that the post heat-treatment doubled the red fluorescence. The obtained CaGa₂S₄-CaS composite doped with Eu²⁺ showed more intense fluorescence rich in color rendering than a commercially available Y₃Al₅O₁₂: Ce phosphor.