The combinatorial material chip approach is an advanced method for inorganic functional materials and it can rapidly discover and optimize novel materials. In this paper, the approach was used to study flourescent material gadolinium aluminate phosphors (Gd1-xAlyOz:Eux). The Gd1-xAlyOz:Eux gradational combinatorial material chips were prepared by ion beam sputtering deposition and two-step annealing. XRD patterns and SEM second electron images indicate that different gadolinium aluminate phases were formed in the combinatorial material chips corresponding to the different Gd:Al stoichiometry. Gd4Al2O9(GAM) and GdAlO3(GAP) were stable phases in Gd2O3-Al2O3 system, and their single phase polycrystal films were easy to synthesize. Under UV light excitation (λex=254 nm), the gradational material library showed all Gd1-xAlyOz:Eux phosphors gave bright red emission (Eu3+5, D0–7F2, 615 nm) and the best matrix for Eu3+ dopant should be GdAlO3. This library screening result was also verified by photoluminescence spectra and absorption spectra.