It is known that hybrid liposomes composed of dimyristoylphosphatidylcholine (DMPC) and micellar surfactant (Tween 20) are effective for encapsulating drugs and for the treatment of meningeal gliomatosis in vivo without toxicity. In this study, we attempted to use these hybrid liposomes as a drug carrier system for the oral administration of insulin using diabetic model rats. The noteworthy aspects were as follows: (a) The hybrid liposomes of 90 mol% DMPC/10 mol% Tween 20 were stable and uniform for more than 4 weeks. (b) The blood glucose level of diabetic model rats decreased after the oral administration of hybrid liposomes including insulin. These results suggest that the oral administration of hybrid liposomes including insulin should be effective for the treatment of diabetes.