Spray pyrolysis method was applied to the preparation of Ce0.6Tb0.4MgAl11O19 green phosphor particles. The characteristics of as-prepared particles such as photoluminescence, crystallinity, and morphology were compared with those of post-treated particles. The as-prepared particles at 1700 degreesC had higher crystallinity and photoluminescence properties compared with those of post-treated particles. The morphology of as-prepared particles obtained at low temperatures changed from spherical shape to plate-like shape after post-treatment at 1400 degreesC for 3 h. The particles directly prepared at 1700 degreesC had the mean size of 0.7 mum and non-aggregation characteristics. This study has demonstrated that without post-treatment processing/annealing, spherical phosphor particles having complex composition could be prepared by a one-step synthesis.