The research include the study of the effect of lead in the form of lead nitrate on some hematological parameters (Hb concentration, total WBC count , differential WBC count) and liver enzymes, glutamate-pyruvate transaminase (GPT) or (ALT) and glutamate-oxaloacetate transaminase (GOT) or (AST) levels during the acute and chronic exposure in experimental mice , the research performed by feeding the mice to two different concentration of lead nitrate 50 ppm/kg and 100 ppm/kg for two exposure periods the acute (10days) and chronic (20 days) . the results showed that the lead in 50 ppm/kg con. in chronic period showed much less decrease in hemoglobin concentration, neutrophils percentage ( 6.9 g/100ml , 12.25% respectively) than in the acute period (9 g/100ml , 18.5% respectively) and an increase in total WBCs count, basophils, eosinophils and lymphocytes percentage (5.01×103,2.25% , 4% and 65.25% respectively) much than in the acute period( 3.11×103 , 0.75% , 0.75% , 63.25% respectively) , AST level increase significantly in the acute period of 100 ppm/kg exposure where as ALT level increase significantly in the acute period of 50 ppm/kg exposure , we also found that females were more hematologically affected with lead compared with males while the AST and ALT levels were high in males than females for both periods .