Long afterglow Sr 3 MgSi 2 O 8 : Eu, Dy phosphor with high brightness was prepared by sintering at high temperature and weak reductive atmosphere. The luminescent properties of this photoluminescent pigment were studied systematically by investigating concentration effects. The analytical results indicated that the main emission peaks appear at 482nm. The excitation and emission spectra of this phosphor show that both of them are broadband. This is ascribed to the 4f7→4f65d1 transition of Eu 2+ in the pigment matrix, which is in good agreement with the calculated value of 470nm, and implies that luminescent centers Eu 2+ occupy the deca-coordinated Sr 2+ sites with the host of Sr 3 MgSi 2 O 8 .