Abstract: In this study,37 Castanea mollissima cultivars were used to study the relationship between the activities and Castanea mollissima browning differences and polyphenol oxidase(PPO),and according to the cluster analysis browning differences of all varieties. The results showed that the browning of different virities was significantly(p<0.05) different according to the cluster analysis of browning differences. 37 varieties could be divided into 5 levels. The differences of PPO activity between cultivars were significantly. By comparison between varieties of degree the browning and PPO activity increased with the Castanea mollissima varieties,it was found that PPO activity,browning degree were beginning to rise,When PPO activity reached 90 U·min-1·g-1,PPO activity against browning began to decrease by clustering the Castanea mollissima browning,the activities of PPO were divided into 5 categories. When Castanea mollissima preferred or improved varieties,PPO activity varieties could be in the first or second activity of the range that choose one of the following as the basis.