In this study, we have screened Eu³⁺- and Tb³⁺-activated candidate phosphors for PDP in the sys-tems of CaO-Gd₂O₃-Al₂O₃ by combinatorial chemistry and investigated the synthetic temperature, optimum com-position and luminescent properties about the candidate phosphors. To construct the emission intensity library by VUV PL, we have synthesized 210 different compositional samples using a polymerized-complex method. Good luminescent samples were identified by X-ray diffraction method. Ca_αGd_0.95-α-βAl_βO_δ : Eu (0.02<α+β<0.04) phos-phors screened as a red phosphor have good color purity than commercial phosphor. In the candidate phosphors of CaGdAl₃O₇ : Tb, CaAl₁₂O₁₉ : Tb, Gd₄Al₂O₉ : Tb and Gd₃Al₅O₁₂ : Tb, CaGdAl₃O₇ : Tb and CaAl₁₂O₁₉ : Tb have shorter decay time than commercial phosphor.