Pectinase,cellulase,hemicellulase,and other enzymes from mandarin orange peel,citrus-grapefruit often be used in processing of Canned mandarin oranges,orange juice,and peeled citrus.The applications of these enzymes are summarized in the article.The characteristics of enzyme are noticed as strong specificity,high catalytic efficiency and mild reaction conditions.With the in-depth study of enzyme application in citrus processing,these enzymes will play an important role in the development of citrus industry.