The niikata pear were treated by 500 nL/L and 1 000 nL/L 1-MCP to study the effects of 1-methylcyclopropene(1-MCP) on the qualities of pear fruit(Pyrus pyrifolia Nakai) during cold storage.The results showed that the decrease of fruit firmness could not be inhibited by 1-MCP during cold storage,but the fruit firmness during shelf life could be maintained after the fruits were cold storage for 120 days,150 days and 180 days.No significant differences were found on the soluble solid content(SSC) and titratable acid(TA) content of pear fruit during cold storage in all treatments.The vitamin C content could be maintained by 1 000 nL/L 1-MCP.In addition,the respiration and ethylene release rate of niikata pear during cold storage were inhibited significantly by 1-MCP,and thus the malondialchehyche(MDA) content and polyhenoloxidase(PPO) activity were also inhibited,then the pear decay rate during 7 days shelf life after cold storage for 180 days was significantly reduced.The decay rate in which treated by 500 nL/L 1-MCP was less than that of 1 000 nL/L 1-MCP.