Abstract: Peach, a climacteric fruit, has quite short storage period and is prone to chilling injury and lignification. As a common and effective treatment for the quality maintenance of fruit and vegetables, 1-MCP is used in postharvest practice. Taking 'Xiahui No. 8' as the experimental material, the effect of 1-methylcyclopropene (1-MCP) treatment (10 μL/L, 12 h) on the quality and physio-biological impacts of peach fruits with two maturities during storage at 20 ℃ was investigated. The results showed that the 1-MCP treatments could inhibit the respiration intensity and ethylene release of the two-mature fruits. On the 4th day of storage, the respiration intensity of the low and high maturity fruits of the 1-MCP treatment was 12.16 mg·kg⁻¹·h⁻¹and 12.82 mg·kg⁻¹·h⁻¹ lower than the control. Compared with the control, the peak value of ethylene decreased by 18.43% and 15.88%.The hardness, reduced ascorbic acid (RASA) and glutathione (RGSH) contents of the 1-MCP-treated fruits were all higher than those of the corresponding control group; simultaneous the treatments could inhibit malondialdehyde (MDA) accumulation, at the end of storage, MDA content of low maturity treatment and control group were 2.35 μmol·g⁻¹FW and 2.54 μmol·g⁻¹FW, meanwhile, compared with the control group, the activities of succinate dehydrogenase and cytochrome oxidase of high maturity treatment were maintained at 0.47 and 2.80 U ·min⁻¹·g⁻¹FW at the end of storage. The activities of peroxidase and superoxide dismutase were delayed in low maturity treatment, and the activities of succinate dehydrogenase and cytochrome oxidase were increased by 32.50% and 20.30%. The results showed that 1-MCP treatment could delay the maturity and aging process of 'Xiahui 8' peach fruit, maintained its quality, and generally had a better effect with lower maturity.