This paper reports a sequence of a Ca 3 YAl 3 B 4 O 15 :xEu 3+ red phosphor prepared using a high-temperature solid-state reaction. At the excitation of 396 nm, the samples emitted intense red emission centred at $623 nm, which could be attributed to the 5 D 0 ! 7 F 2 transition of the Eu 3+ ion. The results showed that the optimum Eu 3+ doping concentration of Ca 3 YAl 3 B 4 O 15 :Eu 3+ phosphor was x = 80 mol%, and the concentration quenching mechanism of Ca 3 YAl 3 B 4 O 15 :Eu 3+ red phosphor belonged to the exchange coupling between Eu 3+ ions. The Commission Internationale de l'éclairage (CIE) coordinates and colour purity of Ca 3 Y 0.2 Al 3 B 4 O 15 :0.8Eu 3+ were calculated as (0.6375, 0.3476) and 95.5%, respectively. Moreover, the red emission of the obtained phosphor Ca 3 YAl 3 B 4 O 15 :0.8Eu 3+ exhibited a low thermal quenching behaviour with an intensity retention rate of 92.85% at 150 C. The above results manifest that the Eu 3+ -activated Ca 3 YAl 3 B 4 O 15 phosphor is predicted to be a promising red luminescent component for white light-emitting diodes.