1. In the patients of Lepra maculosa and nervosa, in which the symptoms are relatively slight and the erythrocyte sedimentition rate and cobalt reaction remained in the normal range, a slight increase of γ-globulin and a slight decrease of albumin were recognized with the slightly increased ratio of β/α of the lipids of α- and β-globulin fractions, especially in Lepra nervosa. 2. In the patients of Lepra tuberosa, in which the symptoms are very severe and the erythrocyte sedimentation rate is markedly accelerated with the deviated Co-reaction to the right side signifying the severe damage of liver function, a marked increase of γ-globulin and decrease of albumin is recognized with the increase of the protein contents of serum. In lipid fractions a large value of β/α is found. 3. In the patients of Lepra tuberosa with red spotted skin which means the revival of the disease also shows the high value of β/α in lipids with the increased quantity of the lipids in α(2) globulin fraction.