The present study includes 70 cases of thalassemia patients from inherited anemia center, Al-Karama hospital in Baghdad / Iraq. Evaluation of the immune system function done for those patients by measuring the number of transformed cell (type T) using PHA and compared with healthy people (control). It was noted that there were significant decrease in the of transformed T cells in thalassemia patients compared to control. When phagocyte cells function studied in vitro and compared with control also significant decrease in the percentage of phagocytic cells than control. Ten samples studied for lymphocyte transformation (type T) of normal healthy people with using Phytic acid and compared with control without Phytic acid, significant increase in the percentage of lymphocyte transformed T cell in compared with control, but when phgocytosis studied in vitro and compared with control show no significant differs. Hemoglobin (Hb), packed cell volume (PCV) and total white blood cell count (WBC) were measured for 20 thalassemia patients and compared with control. Hb and PCV show significant decrease than control while total WBC count show no significant different.