This work is concerned the main biochemical and statistical study on the sera of fifty insulin dependent diabetic patients who were attended at Saddam Central Teaching Hospital for Children (34 males and 16 females), and 25 healthy controls. This investigation was carried out on serum to measure the concentration of total cholesterol, high density lipoprotem-cholesterol and some important trace elements, such as copper, iron, and chromium. The experimental results showed that the mean value of total cholesterol concentration and copper were significantly higher in diabetic children comparing to the healthy children (PO.001), while the mean level of serum chromium was significantly lower than controls (PO.001). There were no significant changes in overall mean concentrations of serum iron and high density lipoprotein in insulin dependent diabetic patients. The effect of the cases ages was also studied in- this work, we have found that the serum total cholesterol was affected by the age of diabetic patients (PO.001) while serum HDL-cholesterol, copper, iron, and chromium levels of diabetic patients were not affected by age. The sex of patients was found to have no influence on the above biochemical parameters.