The decomposition rate of cephalosporin C was measured in order to determine the stable operating conditions for extraction, and the same pH dependence as those reported in the past works was obtained. The physical extraction of cephalosporin C with butyl acetate did not occur since it was amphoteric and the fraction of undissociated form was very low.The reactive extraction and strippting of cephalosporin C were studied by using various extractants and buffer solutions. The reactive extraction occurred when tri-n-octylmethylammonium chloride and carbonate buffer were used as an extractant and buffer, respectively. This was the first example of cephalosporin extraction. Cephalosporin C extracted into organic phase was stripped by acetate buffer solution. In the stripping, the anion exchange reaction between cephalosporin C and acetate occurred.