Under the simulative human physiological conditions，using nano-TiO2 as the control，the interaction of GR-TiO2 with lysozyme（LYSO） was investigated by ultraviolet spectrometry，fluorescence spectroscopy，synchronous fluorescence spectroscopy，three dimensional fluorescence spectroscopy and circular dichroism.The enzyme activity was determined in the presence of GR-TiO2.The results of fluorescence spectroscopy revealed that the endogenous fluorescence of LYSO was quenched by GR-TiO2 and its mechanism was static quenching.The major driving forces were hydrogen bonds and van der Waals′ forces.These results of GR-TiO2 were consistent with that of nano-TiO2.The results of synchronous fluorescence and circular dichroism spectra further demonstrated that the conformation of LYSO influenced by GR-TiO2 was more than that by nano TiO2.The result of enzyme activity indicated that the enzyme activity of LYSO was inhibited more strongly by GR-TiO2.