Abstract: In order to improve the quality of peach fruits during storage periods, authors investigated the effects of the treatment of ‘Okubo’ peach (Prunus persica L.Batsch ) with exogenous ethylene (50-80 μL/L) at different modified atmosphere (MA) storage periods (0, 15 and 30 days). The soluble solids content (SSC), rot index, titratable acid (TA), total sugar, vitamin C contents were measured during storage and after 3-day shelf life at 20℃. The results showed that the treatment with exogenous ethylene at 15, 30 d during MA storage at 0℃ could keep the fruit texture and SSC, and decrease the rot index. Peach fruit treated with exogenous ethylene at the 15th day could keep the content of total sugar and vitamin C, but TA has no significant difference. The research showed that treatment with exogenous ethylene at the 15th day during MA storage had the best effect.