Blue-green phosphor, , was prepared by solid-state reaction and optimized by adding as flux. Temperature-dependent luminescence of phosphor was investigated. Furthermore, the luminescence properties of bright blue-green light-emitting diodes (LEDs) fabricated by incorporating this phosphor with an InGaN-based near-UV chip were also studied based on different forward-bias currents. The results suggest that photoluminescence intensity of can be improved by adding , and luminescence of the prepared phosphor exhibits higher thermal stability than that of commercially available phosphor. It is expected to be a good blue-green phosphor candidate for creating white light in phosphor-converted white LEDs.