The interaction of lysozyme (Lys) and gold nanoparticles was investigated via UV-vis absorption and resonance light-scattering method. There are some changes of the plasmon absorption and resonance light-scattering of gold nanoparticles that were observed via the addition of Lys. The normalized plasmon absorption and resonance light-scattering intensity with gold nanoparticles were both linear with 1-20 nmol/L Lys. A simple model about the component of the gold nanoparticles and Lys complex was established and the calculated result was fitted well in their concentration ratio. Furthermore, the activity analysis of Lys showed that the interaction was weak and nondestructive.