Abstract: AIMTo study the characteristics of the interaction between insulin and liposome. METHODS The interaction between insulin and liposome was studied by fluorescence spectra and microcalorimetry methods. The sample of insulin liposome interaction after separation by supper-centrifugalization or gel filtration was determined by fluorescence and HPLC. RESULTSThe results indicate that there was only little increase in fluorescence intensity and no blue shift of peak in fluorescence spectrum. Fluorescence quenching experiments with NaI and acrylamide as quenchers showed that the K_svs (the slope of Stern-Volmer equation) of insulin were more similar to that with added liposome, indicating low interaction between insulin with liposome. The microcalorimetric results indicate that the heat released during the mixture of liposome with insulin, was 1.98 kcal·mol^-1, suggesting that the reaction belongs to weak reaction. The quantity of insulin in the insulin-liposome mixture sample after separation by ultracentrifuge or by Sephadex G-75 determined by HPLC, the combination percent was only 0.2%, indicating low interaction between insulin and liposome. CONCLUSIONThe interaction between insulin and liposome was weak.