Acute pancreatic necrosis was artificially induced on dogs which were used as test animals by injecting bile of the same dog or olive oil through the pancreatic duct. Those which developed edematous changes were classified as mild cases and others which developed necrotic changes as severe cases. The pancreas was removed as quickly as possible, cut into small pieces, dipped in ether in a refrigerator for a week, and extracted. Further extraction of the sediment was conducted by keeping it in a buffer of Borax-KH(2)PO(4) for one week. Separation percentage by paper electrophoresis was performed by Kobayashi apparatus. The pancreas of dogs removed immediately after death was used as control cases. The results were as follows: In the normal cases (control) a clear separation pattern of albumin, α, β, φ and γ globulin, and f separation was observed. In the mild cases, the separation pattern of β globulin was either not clear or had disappeared, the separation pattern of γ globulin decreased and that of albumin not clear. In the severe cases the separation pattem of β globulin had disappeared completely, and that of albumin had disappeared with the increase in γ globulin.