By loading homogenous and heterogenous visceral antibodies as well as homogenous and heterogenous antisera of organs, extracted from the same or different species of animals previously sensitized by the respecitve antigen of the same and different of animals to the same and also different species of normal ani, als, the author studied the changes in the serum protein pictures and visceral antibody titer in respective group of animals, and obtained the following results. 1. When rabbits are sensitized by the extracts of various viscera (liver, stomach and caecum, etc.) of normal doges or rabbits, a decreasing tendency in the total serum protein can be recognized during and after the sensitization 2. In the sensitization mentioned above, the picture of the serum protein fractions during and after sensitization reveals a decrease in serum albumin and an increase in γ-globulin, and at the same time α-globulin and β-globulin are seen to fluctuate prior to the fluctuation of γ-globulin. Moreover, in the case of sensitization by the heterogenous visceral antigen the changes in the serum protein fractions are more marked than those in the case sensitized by homogenous antigen. 3. The rate of rise in the visceral antibody titer when sentitized by various visceral antigens parallels approximately with the change in γ-globulin. 4. The total protein of serum when loaded with antisera of the homogenous or heterogenous viscera (liver, stomach, duodenum, etc.) to respective species of animals shows a decreasing tendency both during and after the loading of such antisera. 5. As for the loading of the various visceral antisera above mentioned, the picture of serum protein fractions, irrespective of homogenous or heterogenous visceral antisera, reveals a slight decrease in serum albumin and β-globulin, not so marked changed in γ-globulin, and a relative increase in α-globulin. About one week after loading these antisera the serum albumin decreases; γ-globulin increases; and these fractions fluctuate preceding the changes in α-and β-globulin fractions. In addition, one week after the loading α-globulin fluctuates in parallel with the change in γ-globulin, while β-globulin in parallel with albumin. 6. Th production of titer of antibody against these visceral antigens at the time loaded with various visceral antisera approxmately parallels with the changes of γ-globulin. 7. From the fact that the decrease in albumin fraction is more marked in the group loaded with the liver antiserum than in the groups loaded with other visceral antisera as observable in the serum protein picture in the comparative study between the group loaded with liver antiserum and the groups given other visceral antisera, the relative visceral specificity and the course of liver disturbances due to the specificity have been veirfied.