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The reddish-orange phosphors YPO₄:Gd₃₊,Eu₃₊ were synthesized with the high temperature solid-state method at 1100 ℃, and discussions were conducted in respect of the influences of Eu₃₊ ion doping concentration, alkali carbonate,flux and sensitizers on the luminescence properties of YPO₄:Eu₃₊. XRD analysis shows that the synthesized principal phosphor is of the single phase YPO₄. Eu3 + ions have a better doping concentration of 2.5%. Alkali carbonate Na₂CO₃ can effectively improve the photoluminescence intensity of the phosphor. The addition of flux NH₄F can reduce the phosphor calcination temperature from 1100 ℃ to 800 ℃ and facilitate the luminescence center into the crystal lattice. Gd₃₊ ion can effectively transfer the absorption energy to Eu₃₊ ions at the luminescent center, enhancing the luminescence intensity of the phosphor. The chromaticity coordinate analysis shows that the chromaticity coordinate of the phosphor YPO₄:0.025Eu₃₊is (0.61,0.39) which locates within the scope of the chromaticity coordinate of the standard reddish-orange point．