The photoluminescence of Au 2S/Au nanoshell (a nanometer-scale Au 2S core coated by a thin Au shell) is observed. A photoluminescence peak of Au coated Au 2S is observed near the blue-green region. Comparing to the photoluminescence region of bulk Au 2S which is near the orange-red region, the blue-shift photoluminescence of the Au 2S/Au nanoshell mainly attributes to the core/shell nanostructure.