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 phenols concentration and ethylene production of Friar plum was studied. The results indicated that, chilling injury browning of Friar plum developed after 75 or 60 days of storage at (0±0.5)℃ or (3±0.5)℃, but never developed when fruits were stored at (7±0.5)℃, at which temperature, the storage period was short. Moreover, mechanical injury browning developed in pulp near peel after two days of storage at low temperature. Browning symptoms were efficiently reduced by 5μL/L 1-MCP treatment for 12h when fruits were stored at (0±0.5)℃. However, when the storage temperature was (3±0.5)℃ or (7±0.5)℃, fruits treated with 1-MCP showed more serious browning symptoms than untreated fruits. In any case, both two kinds of browning are related to PPO activity and total phenols concentration.