Abstract: Effects of 1-methylcyclopropene(1-MCP) on storage quality and postharvest physiology of bitter gourd fruit were investigated. The harvested bitter gourd fruits were treated with 0.5,1.0 and 1.5 μL/L 1-MCP for 12 h,then the fruit were stored at 20 ℃. During storage,the changes of decay rate,flesh firmness,color,total soluble solids( TSS) and titratable acid( TA) content, ascorbic acid( As A) content, accumulation of superoxide anion(O2-·),hydrogen peroxide(H2O2),activity of catalase(CAT) and peroxidase(POD) were determined. The results showed that compared with the control fruit, 1- MCP treatment suppressed fruit softening,maintained the high levels of As A and TA content and increased TSS content. And the CAT and POD activity of treatments were increased and significantly higher than the control during storage. In addition,1-MCP treatment could suppress the decay rate of fruit,whereas the higher concentration increased the decay rate. Therefore,0.5 μL/L 1-MCP treatment could delay ripening and senescence of harvested bitter gourd fruit and maintain storage quality,prolonging the storage time for above 4 days under 20 ℃.