Twenty seven adult male rats of mean weight 250-300g were divided into 3 groups and studied by the following procedure: group 1 were included of 9 rats which were exposed to 50Hz, 100μT in solenoid for 7 months, group 2: were included of 9 rats which were exposed to 50Hz, 500μT in solenoid for 7 months group 3 control group: were included 9 rats which were kept in normal condition of animal room. All the above groups were kept at roomtemperature of 22^oC and 12/12hr light dark condition. After seven months each rat was anaesthetized with sodium pentobarbital and blood sampling was done from its aorta. The blood sample was used to measure hematocrit by microcentrifuge, hemogolobin by sahli tube, red and white blood cells by hemocytometer. Obtained data were analyzed by the ANOVA and Duncan test at p<0.05 as the significant level. The results showed that the average of hematocrit in group 1 and 2 decreased as compared with control and red blood cells decreased in group 1 as compared with other groups but hemoglobin and white blood cells remained unchanged. In conclusion, these findings demonstrate that EMF may affect some blood factors.