The enzyme peroxidase is widely distributed among the higher plants. Isozymes of peroxidase are known to occur in a variety of tissues in a large number of plant species. In this study, peroxidase isozymes were purified from the extract of pineapple stem through successive steps of ammonium sulfate fractionation, CM-Sepharose CL-6B chromatographies and DEAE-Sepharose CL-6B chromatographies. By these steps, twelve isozymes of peroxidase were obtained. Some properties of the isozymes were studied and compared.