Abstract: In order to control the enzymatic browning of potato during the storage and processing, the potato polyphenol oxidase was isolated and purified, and its enzymatic properties were studied. The crude enzyme fluid of potato polyphenol oxidase (PPO) was obtained by the extraction of buffer solution and centrifugation at low temperature. Then, the crude enzyme fluid was separated and purified through the ammonium sulfate salt fractionation, Sephadex G-25 molecular gel column chromatography desalination treatment, DEAE Sepharose Fast Flow anion exchange column chromatography and Sephadex G-75 molecular sieve gel filtration chromatography to obtain the potato polyphenol oxidase, and some of its enzymatic properties were further studied. The results showed that: the specific activity of purified PPO was 283.0 U·mg^-1, the recovery rate was 16.8%, and the purification fold was 18.6 times. The optimum reaction temperature and pH of the enzyme were 30℃ and 6.5, respectively. When catechol was used as the substrate, the optimal concentration of substrate was 50 mmol·L^-1. The enzyme had strong substrate affinity for pyrogallic acid and resorcinol, and had low substrate affinity for 4-methylcatechol, caffeic acid, gallic acid, hydroquinone, catechol and chlorogenic acid, while having low affinity for N-BOC-tyramine and guaiacol.