In order to study the effect of lead exposure on the hematocrit and hemoglobin values in accordance with the level of lead exposure, twenty-four Sprague-Dawley rats were equally divided into four groups of six rats each. Lead acetate disolved in glucose was injected intraperitoneally six times a week, for four weeks with dose of 0.05 mg/kg/day for group I, 0.5 mg/kg/day for group II, and 5 mg/kg/day for group III. Control group was injected glucose only. Blood samples for the checking of the hematocrit and hemoglobin values, were taking from tail vein of rats before lead injection and on the third, seventh, fourteenth, twenty-first, and twenty-eighth days after lead injection. And also, the concentration of lead and ALA in urine were checked for evaluating the lead absorption. The results were as follows: 1. The alteration of the hematocrit and hemoglobin values of the group I was not significant as that of the control group. 2. In group II, the hematocrit values were significantly decreased from the fourteenth day after lead injection, and the hemoglobin values were decreased from the twenty-first day after lead injection when the concentration of lead in urine was elevated more than $260{mu}g/liter$. 3. In group III, the hematocrit values were decreased from the seventh day after lead injection, and the hemoglobin values were decreased even from the third day after lead injection. And the hemoglobin values were more rapidly decreased than the hematocrit values. 4. In all groups, the correlation coefficient between hematocrit and hemoglobin was highly significant. And the difference between the correlation coefficient of the group III and that of the others was highly significant.