Among the environmental pollutants, cadmium and lead compounds may impair human health. These compounds may inhibit the biological metabolic function of bum.an body and may furthermore cause the disease directly or indirectly. This study was undertaken to investigate the effects of the immune response by intoxication of cadmium chloride and chloride acetate. Cadmium chloride (8.8 mg/kg, in saline 10 ml) and lead acetate (15 mg/kg, in saline 10 ml) were administered by lntraperitoneal injection. After 3 weeks, the rats were intoxicated with the above chemicals and immunized with sheep RBC. After 4 weeks, the immune response of rat spleen cells was measured by the Jerne's technique. The results were obtained as follows; 1. There was no change in leukocyte counts by the intoxication of cadmium chloride or lead acetate. 2. Cadmium chloride or lead acetate reduced hemoglobin contents for most intoxicated and immunized groups. 3. Hematocrits were decreased by the intoxication of cadmium chloride or lead acetate significantly. 4. It was determined that total protein, A/G (Albumin/Globulin), alpha-, beta- and gamma-globulins in rat serum were not changed. 5. Intoxication by cadmium chloride or lead acetate reduced the number of hemolytic plaque to the sheep RBC in rat spleen cells. Therefore, antibody producing of rat spleen cells was suppressed by the intoxication of cadmium chloride and lead acetate.