Abstract: Refolding of lysozyme(LYS) by directly dilution with refolding buffer containing CTAB was performed and the optimal recovery of lysozyme activity was obtained at the molecular ratio of CTAB to lysozyme of 10, in case the denatured lysozyme concentration was over 0.2 mg•ml^-1.Characterization of the structure of the complex formed by CTAB and denatured lysozyme was carried out by means of surface tension measurement, ion-exchange chromatography, fluorescence spectrum, and non-reductive SDS-PAGE.The diversity of the complex was identified by the changes of surface tension, elution behavior in ion-exchange chromatography, as well as the electrophoretic migration in the non-reductive SDS-PAGE, all of which was shown to be a function of the molecular ratio of CTAB to protein.The changes of the composition and structure of the CTAB-protein complex were identified, as shown by the yield of lysozyme activity as a function of incubating time.The above results are of fundamental importance for the development and application of surfactant assisted protein refolding.