In 11 patients of chronic schistosomiasis and 5 rabbits of experimentally induced acute schistosomiasis, the paper-electrophoretical patterns of serum proteins were investigated. The remarkable decrease of albumin and notable increase of gamma globulin were observed in 8 patients of chronic schistosomiasis with liver cirrhosis, the diagnosis having been precisely determined on the basis of histological findings of liver biopsy, liver function tests and so on. In 3 patients with no significant histo-pathological finding, no change was observed in the pattern of serum proteins. The pattern of rabbits at 5 or 6 weeks after the percutaneous infection of cercaria, appeared to show the gradual decreased of albumin, and increases of alpha, beta and then globulin in the successive order.