Abstract: Polyphenoloxidase ( PPO) widely existed in all kinds of organisms, such as botanies, animals, funguses, bacteria and so on. It is also the main reason that leads to enzymatic browning. During food storage and processing, relevant technology are used to inhibit the activity of PPO in order to protect the nutrition, flavor and exterior quality from being damaged in a reasonable time.The inhibition of PPO, the effect of different methods on PPO activity, the research progress in the inhibition kinetics, the conformational changes of unfolded PPO and the unfolding models were summarized.At last, the development of the research was prospected in this review.