A method which facilitates the separation of the conjugated γ-globulin from both non-labeled antibody and unreacted peroxidase by use of DEAE-cellulose chromatography was shown in this paper. Using the new method of conjugation reported by Nakane and Kawaoi (1974), the isoelectric point of the peroxidase-labeled antibody was found appreciably to shift toward lower pH than that of the original antibody. Paying attention to the difference of the isoelectric point between labeled and unlabeled antibodies, DEAE-cellulose chromatography was performed to isolate labeled antibody. The enzymelabeled antibody was eluted with 0.025M-0.05M phosphate buffer (pH 8.0), while the non-labeled antibody was eluted at the concentration of 0.005M-0.01M phosphate buffer (pH 8.0) and the modified peroxidase was eluted at higher concentration of 0.25M phosphate buffer (pH 8.0).