Diabetes Mellitus is a chronic and complex disease, requiring continued life long management aimed at reducing the high morbidity and premature mortality caused by chronic complications. In both type ? and type ?? diabetes, late diabetic complications in nerve, vascular endothelial, and kidney, increased oxidative stress and it is consequences of either increased production of free radical, or reduced antioxidant defenses, arise from chronic elevation of glucose. This work is concerned the main biochemical and statistical study on the sera of thirty healthy control subjects (13 female & 17 male), and thirty four children with insulin dependent diabetes mellitus (16 females & 18 males). They were attended at Al -Kahdmia Teaching Hospital & National Center of Diabetic. This investigation was carried out on serum to measure the concentrations of homocysteine, vitamin A ,vitamin C & vitamin E by using High Performance Liquid Chromatography(HPLC-10 AVP) analysis. The experimental results showed that the mean value of homocysteine concentration was significantly higher in diabetic comparing to the healthy control subjects (p<0.001), while the mean level of serum vitamins (A, C& E) were significantly decreased in diabetic compared to healthy control subject (p<0.001). From the results of this study were found the age was effect groups on the level of both parameters (antioxidant vitamins and homocysteine) (p<0.001). There was no significant difference in levels of vitamins and homocysteine between females and males in both groups diabetic and healthy control.