This report presents the luminescence properties of Ce 3+ and Pr 3+ activated Sr 2 Mg(BO 3 ) 2 under VUV–UV and X-ray excitation. The five excitation bands of crystal field split 5d states are observed at about 46729, 44643, 41667, 38314 and 29762cm −1 (i.e. 214, 224, 240, 261 and 336nm) for Ce 3+ in the host lattice. The doublet Ce 3+ 5d→4f emission bands were found at about 25840 and 24096cm −1 (387 and 415nm). The influence of doping concentration and temperature on the emission characteristics and the decay time of Ce 3+ in Sr 2 Mg(BO 3 ) 2 were investigated. For Pr 3+ doped samples, the lowest 5d excitation band was observed at about 42017cm −1 (238nm), a dominant band at around 35714cm −1 (280nm) and two shoulder bands were seen in the emission spectra. The excitation and emission spectra of Ce 3+ and Pr 3+ were compared and discussed. The X-ray excited luminescence studies show that the light yields are ∼3200±230 and ∼1400±100photons/MeV of absorbed X-ray energy for the samples Sr 1.86 Ce 0.07 Na 0.07 Mg(BO 3 ) 2 and Sr 1.82 Pr 0.09 Na 0.09 Mg(BO 3 ) 2 at RT, respectively.