Abstract: Using Jiang'An Dabai plum as experimental material, the physiology and quality changes of plum were treated with chitonsan and Cl O2 individually treatment and together in sequence.The results showed that the chitonsan or Cl O2 individually treatment were able to decrease the respiration rate and weight loss of the plum, the reductions in good fruit rate, contents of vitamin C and soluble solid were effectively retarded. The combination of chitosan and Cl O2 could reduce the weight loss and increase the good fruit rate more availably. With treating Jiang 'An Dabai plum in sequence, chitosan coating after Cl O2 treatment proved to be more effective in decreasing decay rates, and effectively extend the shelf-life of plum.The results could provide evidence of reasonable preservation of Jiang'An Dabai plum.