Sr2CeO4 phosphor particles were prepared by spray pyrolysis at various preparation temperatures. The effect of preparation temperatures on the morphology, crystal structure and photoluminescence characteristics of the post-treated Sr2CeO4 phosphor particles was studied. Phase pure Sr2CeO4 phosphor particles were not produced by spray pyrolysis without post-treatment. The optimum post-treatment temperature to produce the Sr2CeO4 phosphor particles with high photoluminescence intensity was 1,000 °C in spray pyrolysis. The spherical morphology of the as-prepared particles obtained at high preparation temperatures above 1,400 °C had maintained after post-treatment at 1,000 °C. The relative photoluminescence intensities of the Sr2CeO4 phosphor particles varied with the preparation temperatures in the spray pyrolysis. The as-prepared particles obtained by spray pyrolysis at preparation temperatures below 1,400 °C converted into phase pure Sr2CeO4 phosphor particles after post-treatment at 1,000 °C. The optimum preparation temperature of the as-prepared particles was 1,400 °C to produce the Sr2CeO4 phosphor particles with spherical shape and high photoluminescence intensity in the spray pyrolysis.