Spray pyrolysis method was applied to the preparation of submicron Ce1-xTbxMgAl11O19 phosphor particles. The characteristics such as photoluminescence, crystallinity, and morphology were investigated under various preparation conditions. While the as-prepared particles by spray pyrolysis at temperature of 900°C had amorphous phase, the particles calcined above 1400°C had phase-pure magnetoplumbite structure, and its crystallinity increased with increasing the calcining temperature. The as-prepared particles had spherical morphology, submicron size, and narrow size distribution. The mean size of the particles increased from 0.5 to 1.4 µm when the spray solution concentration increased from 0.03 to 1.5 M. After calcination, the particles showed 545 nm green emission characteristic of Tb3+ ions with optimum excitation at 280 nm. The maximum luminous intensity was obtained at x=0.4. The optimum calcining temperature for good brightness was 1500°C. Particles directly prepared by spray pyrolysis at 1500°C show good green emission characteristics and maintain its sphericity and non-aggregation characteristics.