Abstract: 【Objectives】This study aimed to investigate the effects of polyphenol treatment on the postharvest quality and reactive oxygen species(ROS) metabolism of sweet cherries under room temperature conditions,in order to provide a new way to maintain the quality of sweet cherry fruit and extend the shelf life. 【Method】The experiment utilized four monomeric polyphenols(caffeic acid,catechin,chlorogenic acid and procyanidin) to treat sweet cherries,with deionized water treatment as the control group. Changes in sweet cherry quality,ROS,non-enzymatic antioxidants content,antioxidant enzymes activity,and cellular membrane lipid peroxidation during storage at 20 ℃(0-10 d) were measured. Additionally,a correlation analysis was conducted between the quality of sweet cherries treated with polyphenols and the characteristics of the antioxidant system. 【Result】Compared to the control group,the treated sweet cherries exhibited a greatly reduced weight loss rate. Polyphenol treatment decreased the respiration rate during storage,reduced the excessive consumption of internal nutrients,maintained higher levels of titrable acid(TA) and vitamin C(Vc),and demonstrated increased antioxidant enzyme activity,anthocyanins,total phenols,total flavonoids,and antioxidant capacity. It also inhibited the production and accumulation of superoxide anions(O2-·) and mitigated the degree of lipid peroxidation in sweet cherry cell membranes. Among the four monomeric polyphenols,procyanidin showed the best treatment effect. On the 10th day of storage,sweet cherries treated with procyanidin had the lowest weight loss rate(1.36%) and decay rate(3.49%),a decrease in Vc content of only 35.36%,an anthocyanin content of 0.24 g/kg,significantly higher than control group(P<0.05,the same below),total antioxidant capacitr significantly increased by 62.61% compared to control group, and only a 52.45% increase in malondialdehyde(MDA) content. Weight loss rate was extremely significantly positively correlated with decay rate,MDA content and O2-· production rate(P<0.01, the same below),and extremely significantly negatively correlated with Vc content,non-enzymatic antioxidants(total phenols, total flavonoids, anthocyanins) content and total antioxidant capacity,and significantly negatively correlated with TA content. 【Conclusion】Polyphenol treatment can inhibit oxidative senescence in sweet cherries caused by ROS accumulation,effectively preserve the nutritional value of the fruit,and extend its shelf life. The best preservation effect is achieved by treating with anthocyanins, thereby maintaining the integrity of the cellular membrane structure,effectively preventing the decline in antioxidant capacity,and delaying fruit senescence.