A new blue-emitting chalcogenide phosphor, Ce3+-activated CaLaGa3S6O, with a high purity crystalline was synthesized by a two-step solid-state reaction. Photoluminescence properties of CaLaGa3S6O:Ce3+ were investigated comparatively with the commercial blue-emitting phosphor BaMgAl10O17:Eu2+. It shows a more perfect and efficient broad absorption band around the 398 nm emission of the commercial near ultraviolet light-emitting diodes (LEDs), and presents a comparable blue-emitting performance. The blue light-emitting LED with the CIE chromaticity coordinates of (0.147, 0.089) was successfully fabricated by precoating CaLaGa3S6O: Ce3+ phosphor onto a 398 nm-emitting InGaN chip. All these results indicate that CaLaGa3S6O: Ce3+ is a promising blue phosphor candidate for white LEDs. (C) 2008 Elsevier B.V. All rights reserved.