For the purpose of determining the effects of carbon tetrachloride (CCl(4)), trichloroethylene, and tetrachloro-ethylene on the changes in serum protein fractions and the body weight, we injected 1.5ml/kg of these compounds every other day into Cb strain mica, and also 10mg/mouse of A. T. P. and Xanthine was injected every other day 15 times into the animals with CCl(4) poisoning in order to find out the effects of these drugs and obtained the following results. 1. Every group of the mice with experimental CCl(4) poisoning, trichloro-ethlene and tetracbloro-ethylene poisoning, showed a tendency of a decrease in albumin fraction and an increase in β-globulin fraction. Such changes were especially marked in the group with CCl(4) poisoning. 2. As for the change in their body weight, the group with CCl(4) poisoning alone demonstrated clearly a decrease in the body weight, but the other groups did not show any marked change. 3. It was recognized that both A. T. P. and Xanthine had a slight inhibitory effect on the decrease of the albumin, the increase of β-globulin, and the diminution of the body weight, in the CCl(4)- poisoning group.