’Dashi Early Ripening’ plums were treated with 0.1,0.5,1 μL·L-1 1-methylcyclopropene(1-MCP)at ambient temperature for 12 h following harvest to evaluate the effectiveness of 1-MCP in extending the shelf life.The fruit firmness,soluble pectin,malondialdehyde(MDA)content,respiration rate,superoxide dismutase(SOD)and catalase(CAT)activities as well as soluble sugar and titratable acidity content of the treated plums were measured over thereafter 12 d during which the plums were stored in ambient temperature.The result showed that the plums treated with 1 μL·L-1 1-MCP remained consumer quality better than that with the other treatments.Their firmness was 249% higher than that of control on the 3rd d of storage,their MDA content was 40% lower than that of control on the 9th d of storage,the titratable acidity was 16.5% higher and the soluble sugar content was 25% higher than that of control at the end of the storage.The treatment with 1 μL·L-1 1-MCP lowered the respiration rate and soluble pectin content,and retarded the respiration peak in comparison with control.The treatment also maintained relative higher SOD,CAT activities.It was concluded that 1 μL·L-1 1-MCP treatment was efficient for extending the shelf life and maintaining the quality of ’Dashi Early Ripening’ plums.