Novel LaMgAl 11 O 19 :Pr 3+ phosphors for blue light pumped white light emitting diodes (w-LEDs) were prepared via a solid state reaction. The structure and luminescence properties were investigated. The LaMgAl 11 O 19 :Pr 3+ phosphors emitted a yellow light under excitation at 446nm, which contains a green emission band, a red emission band, and a weak near infrared emission band. Concentration quenching, due to non-radiative energy transfer between Pr 3+ ions via the exchange interaction was observed when the Pr 3+ ion concentration was 0.1mol. The colour coordinate for the yellow LaMgAl 11 O 19 :0.1Pr 3+ phosphor was calculated to be (0.4497, 0.5306). These results indicate that the LaMgAl 11 O 19 :0.1Pr 3+ phosphor can be combined with blue LED chips and can be widely used in w-LEDs application.