Abstract: 【Objective】 To study the effects of delayed precooling and hydrogen peroxide(H₂O₂) fumigation on the quality and physiological characteristics of flat peach during storage. 【Methods】 After stacking in the shade for 0,2,4 and 6 hours,the samples were pre-cooled to 2℃ by tunnel-type in-situ differential pressure equipment and fumigated with 1% H₂O₂ for 5 minutes,respectively,and stored in a fresh-keeping storehouse with (0±0.5)℃ and 85% relative humidity,the physiological indexes of fruits were measured every 7 days. 【Results】 The time required for the fruits to precool to the target temperature by differential pressure at 0 and 2 h was shorter than that at 4 and 6 h.delayed precooling combined with H₂O₂ fumigation inhibited the respiration of fruits,the rate of decay,the rate of weight loss and the activity of PPO were decreased,the activity of CAT was increased,the hardness,the content of soluble solids and vitamin C were maintained,and the ability of scavenging free radicals was enhanced,which inhibited the increase of MDA content and browning of fruit flesh,kept the integrity of fruit cell membrane,delayed the aging process of fruit and improved the fresh quality of fruit. 【Conclusion】 The storage quality of flat peach can be improved by post-harvest pre-cooling combined with proper preservatives.The earlier the pre-cooling time,the better the retention of nutrients and flavor substances of fruits.