The luminance degradation of BaMgAl10O17:Eu2+(BAM) caused by baking at 600 degrees C was studied. The dissolution of Si-N into BAM lattice lead to only a reduction in the lattice parameters. Under UV excitation, the Si-N codoping enhanced the luminescent intensity by a factor of 110% for the as-received phosphors and by a factor of 122% for phosphors baked at 600 degrees C for 1 h. This could be attributed to the stable local structure surrounding the Eu2+ ions and the lower electronegativity of nitrogen. The proposed method is expected to be potentially applicable to other aluminate phosphors with higher stability and photoluminescence.