The changes of solubility, emulsibility, ultraviolet absorption spectroscopy, fluorescence emission spectroscopy and surface hydrophobicity of peanut proteins (PP) were investigated using the methods of 1-naphthalenesulfonicacid-8-(phenylamino)-sodium salt (ANS), ultraviolet and fluorescence spectroscopy. The results showed that, with the increasing of xylitol and mannitol, the solubility of PP increased within pH 3.0～6.0, reached minimum value almost at pH 4.0, while the emulsibility increased first and declined finally. We supposed that the tyrosine was wrapped into the inner core of PP, while the tryptophan exposed to the surface of PP, resulting in the fluorescence intensity of them reduced with the increasing of xylitol and mannitol. The surface hydrophobicity was found increasing gradually when treated with xylitol, while that of mannitol increased first and then declined finally.