Abstract: Abstract: 【Objective】 The effects of methyl jasmonate (MJ) on cold resistance, reactive oxygen species (ROS) metabolism and Ca2+-ATPase activity of postharvest banana fruit were investigated in this paper. 【Method】 Banana peels were treated with 10 µM MJ and incubated in vitro at 7 ℃ for 10 days. The chilling injury index, cell membrane permeability, content of H2O2 and O2－, activity changes of CAT, APX, NADPH oxidase and Ca2+-ATPase were determined.【Result】Compared to control peels, the chilling injury index of MJ treated peels was less and the increase of cell membrane permeability was slower. Moreover, MJ treatment induced the increase of H2O2 content and O2－ production and maintained their high levels before 4 days. However, MJ treatment reduced the activities of CAT and APX and maintained low activity before 4 days. MJ treatment was also found to induce the activities of NADPH oxidase and Ca2+-ATPase of banana peels.【Conclusion】The reactive oxygen species induced by MJ might serve as signal moleculars and be involved in chilling injury and chilling resistance of banana peels, and they might also induce calcium signaling. Key words: Methyl jasmonate ; Chilling injury; Reactive oxygen species; Banana peel