Eu2+-doped α-sialon phosphor was synthesized and structures and various luminescence properties were studied. High crystalline Ca0.8Al2.8Si9.2O1.169N14.94 phase was successively obtained for undoped and Eu2+-doped samples. Eu2+-doped α-sialon phosphor exhibited wide absorption in ultra violet (UV) and visible range, and high broad emission band peaking at from 570 to 582 nm. The optimum compositions and process conditions was obtained from 0.75 mol% Eu2+–doped Ca0.8Al2.8Si9.2O1.169N14.94 fired at 1650 °C for 2 h in 30% H2–70% N2 atm. In addition, fabrication of UV-light emitting diode (LED) lamp using this phosphor was conducted and the optical properties were measured. Relative quantum efficiency of the phosphor and luminous efficiency of the lamp were 83.66% and 35.28 lm/W, respectively. Those results indicated that Eu2+-doped α-sialon phosphor in this study was a good candidate for UV-LED light source.