Increasing evidence suggests that oxidative stress is important in the pathogenesis of diabetes shows that it plays a role. Oxidative stress is also a diabetic it appears to be a factor causing complications. Reactive oxygen environmental factors such as species, ionizing radiation and chemical carcinogens factors as well as endogenous processes such as mitochondrial energy metabolism it is produced by. Reactive oxygen species produced endogenously or exogenously, it can simultaneously attack lipids, proteins, and nucleic acids in living cells. In these ways, excess glucose metabolites as lead to the development of diabetic complications may cause pancreatic β-depletion through a number of potential mechanisms can also cause cell damage. However, common to all these pathways production of reactive oxygen species, excessive and long-term chronic oxidative changes in insulin gene expression and insulin secretion by causing stress defects as well as increased apoptosis. Cellular oxidative various methods have been developed to identify biomarkers of stress; some of these are important for antioxidant defense in diabetes and its complications and can be recommended for sensitive evaluation of oxidative damage.