Pulp browning seriously limits the dietary property and commercial value of plum fruit. In order to elucidate the browning mechanism of plum and to inhibit pulp browning, the effect of 1MCP treatment and different storage temperature on chilling injury browning, mechanical injury browning, PPO activity, total phe nols concentration and ethylene production of friar plum was studied. The result s indicated that, chilling injury browning of friar plum developed after 75 or 6 0 days of storage at (0±05)℃ or (3±05)℃, but never developed when fruits wer e stored at (7±05)℃, at which temperature, the storage period was short. Mor eo ver, mechanical injury browning developed in pulp near peel after two days of st orage at low temperature. Browning symptoms were efficiently reduced by 5μL/L 1MCP treatment for 12h when fruits were stored at (0±05)℃. However, w hen the storage temperature was (3±05)℃ or (7±05)℃, fruits treated with 1M CP showed more serious browning symptoms than untreated fruits. In any case, bot h two kinds of browning are related to PPO activity and total phenols concentrat ion. 