Vi and O antigen fractions have been obtained in purified as well as separated forms from a crude extract of Salmonella typhi Ty-2 strain. The method applied the use of alcohol fractionation as well as salt fractionation of the material on an inorganic column bed. Alcohol fractionation alone neither separated nor purified the antigens significantly. When cetyl pyridinium chloride (CPC) was maintained in constant concentration in the elution solvents, the Vi and O serologically active materials could not be eluted by the usual alcohol–water solvents, but could be removed in separated and purified forms by salt solvents (MgCl2). The essential requirement of CPC in the fractionation is discussed.