Abstract: The aim was to find out the characteristics of active oxygen metabolism and fruit softening in the process of postharvest fruit ripening and senescence which were stored in normal temperature. Taking postharvest fruit (Cucumis melo L‘. Hetao’) as experiment material, physiological indices of different storage time were studied. The results showed that: (1) with the extension of storage time, the content of active oxygen increased, including O₂-·production rate increased significantly, while the content of H₂O₂ presented bimodal changes. (2) The activity of SOD showed the trend of declining first and then rising. However, the activities of POD, CAT and APX were firstly increased and then decreased. They reached peaks at different time and maintained high activity levels for a period and then begun to decline. (3) At preliminary storage, LOX and PG activities were all extremely low, and then rose rapidly. LOX activity fell slightly from 5 d of storage, while PG activity showed a trend of rising volatility from 4 d to the end of the storage. Excessive accumulation of active oxygen exacerbated the fruit senescence in fruit storage time; meanwhile PG and LOX all participated in fruit softening.