Five Bakhtiari rams, one year old, were used in this study. These rains were looked after for two weeks to confirm their health. Blood and bone marrow samples were collected as blanks from jugular vein and sternum, respectively. For induction of subacute poisoning, each sheep received 3.5 mg/kg B.W. copper sulphate daily for 10 days. Blood samples were taken from jugular vein four hours after givening copper sulphate solution. After the last blood sampling, bone marrow sample were also taken from each ram. Hematological parameters (PCV, Hb, RBC count, WBC count, neutrophil, lymphocyte, eosinophil and monocyte) were measured in blood samples and M/E ratio was measured in bone marrow samples. Clinical parameters (respiratory rate, heart rate, temperature and ruminal contraction) were noted each day. The results indicated that hematocrit, RBC count, lymphocyte and eosinophil decreased significantly but WBC count and neutrophil increased (P<0.05). Heart rate and respiratory rate also increased significantly after poisoning (P<0.05). Variation in M/E ratio was not significant (P>0.05).