Growth hormone deficiency is a condition that occurs when a limited volume of growth hormone is released by the pituitary gland since growth hormone deficiency causes growth delays, short stature, and overall physical development delays. symptoms differ based on the age at which they occur .Aim of this study Estimating the level of growth hormone serotonin ,IGF-1 and Chromogranin A before and after with treatment recombinant growth hormone and It is the first study in Iraq that sheds light on the relationship between Chromogranin and other variables ( somatostatin, IGF-1,GH) ,also the prediction of Chromogranin A as a newly biochemical marker in children with growth hormone deficiency. In this study, 30 samples were collected from children between the ages of 4-12 years who suffer from growth hormone deficiency. Different biochemical markers are measured such as Growth Hormone (GH), Insulin-like growth factor-1(IGF-1), Serotonin, Chromogranin A. The results of measurements are compared with 30 samples of healthy children. After examining the results, it was found that the level of growth hormone was low compared to a control group, and a significant difference appeared (P≤0.05). While it was found that high levels of (IGF-1, Serotonin, Chromogranin A) of blood serum compared with the healthy group with a high-significant difference (P<0.001). low levels of Growth hormone and IGF-1 in the serum can be used in the diagnosis of Growth hormone deficiency.