BaAl2S4∶Eu2+ nanoparticles with a size distribution of 50—150 nm were prepared by the sol-gel method. The particles were near spherical and had an intensive green emission when they were excited at 254 nm, after calcining at 1000 ℃ in a mixture of H2S(volume fraction 10%)+N2(volume fraction 90%) for 1.5 h. X-ray diffraction patterns indicate that BaAl2S4∶Eu2+ has a cubic structure. The emission and excitation spectra show that emission was from the 4f65d4f7 transition of the activated Eu2+. The highest photoluminescence(PL) luminance is 420 cd/m2. This study indicate that the BaAl2S4∶Eu2+ could be used as photoluminescent nanocomposite materials.