Abstract: The dynamic process of PEGylated lysozyme and native lysozyme refolding were studied The dynamic process of PEGylated lysozyme and native lysozyme refolding were studied by circular dichroism and fluorescence spectrum.Results showed that PEGylation could change lysozyme refolding kinetic process,and make lysozyme refold at lower denaturing agent concentration.Fluorescence spectrum analysis showed that PEGylation has obvious effect on formation of hydrophobic microenvironment during lysozyme refolding process.PEGylation stabilizes the “molten globule” of lysozyme in refolding process,thus increasing the ratio of right refolding of lysozyme.