. Reregulation of biochemical profile of host as a result of host cells-pathogen interaction may involve in pathogenesis of toxoplasmosis disease. The biochemical parameters in the placenta of Toxoplasma-infected pregnant women and non-infected pregnant women (control group) were investigated The criteria taken into consideration are: Superoxide dismutase (SOD) , Peroxidase (Px) , Glutathione- S- transferase (GST) , Lactate dehydrogenase (LDH) , Aryl esterase (AE) , Acetylcholine esterase (AchE) , Vitamin A,C and E As well as placental electrolytes including: Sodium (Na+) , Potassium (K+) , Chloride (Cl-) , Calcium (Ca++) , Selenium (Se) , Cupper (Cu) , Zinc (Zn) , Iron (Fe) , Magnesium (Mg) and Manganese (Mn). The results showed: a non-significant increase in the activity of SOD, GST, LDH and AchE during 6-9 months, and activity of AE during 1-3 months, were determined whereas the activity of Px was decreased in all periods of pregnancyA non- significant increase in the level of vitamin E and non-significant decrease in levels of vitamin A and C during pregnancy periods in placentae of infected pregnant Were observed. . A significant increase (p≤0.01) in levels of Na+ and K+ during 1-3 months and Ca++ during 3-6 months, whereas the level of Cl- decreased during pregnancy periods. A significant increase (p≤0.01) in levels of Seand Mg during 6-9 months and a non- significant increase in level of Cu during 1-3 months and 6-9 months, whereas the level of Zn, Fe and Mn significantly decreased in all periods of Pregnancy in placenta infected women.