Daily doses of phenylmercuric acetate arranged in 30 γ(group Ⅰ). 3 γ (group Ⅱ) and 0.3 γ (group Ⅱ) were administered respectively to rabbits for 90 days. The chief histopathological changes in the organs and the analytical data on mercury residues in the excretion and liver were as follows. 1. Kidney: In group Ⅰ, severe degrees of vacuolization and cloudy swelling were occurred in the epithelial cells of proximal convoluted tubules and severe cloud. swelling and coagulative necrosis were observed in the proximal straight tubules. There were many hyaline casts in the collecting tubules In group Ⅱ, moderate degrees of vacuolization and cloudy swelling were observed in the epithelial cells of proximal convoluted tubules and moderate cloudy swelling and coagulative necrosis were encountered in the proximal straight tubules. A little numbers of hyaline casts were located in the rumen collecting tubules. In group Ⅲ. slight degree of cloudy swelling were observed in the epithelial cells of proximal convoluted and straight tubules. 2. Liver: In group Ⅰ, cloudy swelling, fatty changes and coagulative necrosis were observed in the central zone of hepatic lobules. Dissociation of hepatic cell cords was encountered. Hyperplsia of hepatic cells were remarkable in group Ⅱ. No Pathological changes were observed in group Ⅲ. 3. Spleen: Deposition of hemosiderin pigment was preminant in group Ⅰ and small amount of the pigment was observed in group Ⅱ. There were no pathological changes in group Ⅲ. 4. Adrenal. colon and heart: No pathological changes were detected in all 3 groups. 5. In an average about 76.5% cf mercury excreted from group Ⅰ, 85.4% from group Ⅱ and 73.8% from group Ⅲ. 6. Mercury content in the liver was 0.03488 in group Ⅰ, 0.00378 g and 0.00066 g in group Ⅱ and group Ⅲ respectively. 7. In general, as to increased mercury doses the concentration of mercury accumulation in the liver became higher, however, the accumulation quantity against a total amount of mercury doses showed an adverse trend. In other word, the quantity of mercury accumulation was not increased proportionately by higher dose of mercury.