Abstract: The fruits of ‘Fengtang Plum’ were used as experimental materials and were soaked in 150 μmol·L^-1 exogenous melatonin solution（MT） for 20 minutes, and treated with water for 20 minutes was served as control（CK）.After drying, the fruits were stored at room temperature of（25±1）℃ to determine the effects of treatment on the fruit quality and physiological indexes of postharvest ‘Fengtang Plum’,in order to provide a reference for the theoretical research on the storage and presercation of ‘Fengtang Plum’.The results showed that exogenous MT significantly inhibited the decreasing of fruit firmness, titrable acid（TA） content and ascorbic acid（ASA） content, inhibited the degradation of chlorophyll, anthocyanin and the production and accumulation of malondialdehyde（MDA）.Exogenous MT treatment effectively improved the contents of soluble solid content（SSC）,soluble sugar, soluble protein, free proline and reduced glutathione（GSH） in fruits.Exogenous MT treatment decreased the activity of lipoxygenase（LOX）,and effectively increased the activities of phenylalanine ammonia lyase（PAL）,superoxide dismutase（SOD）,catalase（CAT）,ascorbic acid peroxidase（APX） in fruits.At the same time, the treatment of exogenous MT also slowed down the deterioration of fruit sensory quality and kept the fruit color and flavor better.In summary, the treatment with 150 μmol·L^-1MT solution can effectively slow down the quality decline and maintain the physiological characteristics of ‘Fengtang plum’,thereby improving the storage characteristics of ‘Fengtang Plum’ fruit at room temperature.