In diabetes mellitus, the high incidence of microvascular and atherosclerotic disorder has been seen which are associated with abnormalities of erythrocyte composition , rheological function and with increased oxidative stress among many other factors. Human erythro-cytes are perhaps the cells most exposed to peroxidation damage by free radicals. In view of this erythrocyte membrane composition of type I diabetic patients was analyzed before and after supplementation of vitamin (E +C) along with insulin and compared with those pa-tients who were on only insulin treatment. All Subjects were selected from Out Patient de-partment of Pad. Dr. D.Y. Patil Medical College: Pimpri and Dr. V.M. Medical College: So-lapur during the period of April 2006 to April 2008. The result showed , significantly de-creased (p< 0.001) concentration of Glycated hemoglobin, serum MDA and membrane cho-lesterol and significantly increased erythrocyte reduced glutathione, membrane phospholip-ids ( p<0.05,p<0.001 respectively) after three months follow up of vitamin ( E+C) supple-mentation along with insulin in type I diabetic patients. The present study may conclude that supplementation of vitamin ( E+C) along with insulin protect the erythrocyte mem-brane composition against such oxidative deterioration and may minimize variety of hema-tological abnormalities which further causes the complications in type I diabetic patient.