Abstract: The effect of preharvest salicylic acid combined with postharvest 1-MCP treatment on plum during postharvest storage was investigated. In this experiment, plum were treated with preharvest salicylic acid 1.0 mmol/L, and then were fumigated with 1 μL/L 1-MCP. To reveal the mechanism, rot ratio, water loss ratio, malondialdehyde content, total soluble solids content, titratable acid content, V_C content, the production rate of O₂⁻·, H₂O₂ content, peroxidase, superoxide dismutase, catalase of activity were measured. The results showed that, preharvest salicylic acid combined with postharvest 1-MCP treatment could effectively inhibit rot ratio and water loss ratio, maintain hardness and total soluble solids and titratable acid and V_C content, delay the increase of malondialdehyde content, H₂O₂ content and the production rate of O₂⁻·. The activities of peroxidase, superoxide dismutase, catalase were significantly provided. At the end of storage 60 days, the rot ratio of CK, SA, 1-MCP, SA+1-MCP four treatment groups were 11.6%, 7.7%, 9.1% and 5.3%, respectively, SA+1-MCP treatment maintained better storage quality of plum fruit. These results indicated that preharvest salicylic acid combined with postharvest 1-MCP treatment could maintain the storage quality and delay plum fruit senescence. The above results will provide a theoretical basis for the application of the postharvest storage and preservation technology of plum.