Abstract: The experiment was conducted to investigate the effects of arabinogalactan (AG) immersion treatment on the postharvest storage characteristics of Qingcui plum and the feasibility of using it as a preservative treatment. In this experiment, the fruit color difference, firmness, weight loss, decay rate, relative conductivity, respiration rate, ethylene production rate, titratable acid, soluble solids, ascorbic acid, total phenols, flavonoids, free amino acids and their metabolism-related gene expression were measured in Qingcui plum fruits stored at room temperature for 15 d. The results showed that 5 g/L AG immersion treatment could delay the coloration process of plum fruit and the decline of fruit firmness and its effect was significantly better than that of 10 g/L AG immersion treatment, 5 g/L AG immersion treatment could reduce the postharvest respiration rate and ethylene production rate, while the ascorbic acid content of 5 g/L AG-treated fruit was higher than that of control fruits, and the weight loss rate and decay rate of 5 g/L AG-treated fruit were significantly lower than that of control (P<0.05). Besides, 5 g/L AG treatment could elevate the free amino acid content of Qingcui plum fruit by regulating the expression of diverse amino acid metabolism related genes. On the whole, 5 g/L AG treatment has a promising application in the postharvest preservation of Qingcui plum.