In order to clarify whether the myrosinase contains only thioglucosidase, or thioglucosidase and sulfatase, chromatographic behaviors of the myrosinase on cellulose ion exchanger were studied. Myrosinase showed 2 peaks by the chromatography on TEAE-cellulose at pH 8.5, but the fractionation of the 2 enzymes was not accomplished. It was concluded that the 2 peaks was not ascribable to an artifact but the 2 closely resembled species of myrosinase existing in the sample solution. Chromatographic separation of the 2 enzymes on DEAE-cellulose resulted in failure. These results confirmed that the myrosinase was a single β -thioglucosidase originally.