Researches on the mechanism of abscission of plant organs have important implications for regulating plant growth and improving out-put and quality of agricultural products. Abscission of plant organs was a complex physiological process. Abscission layer could regulate physiological and biochemical method in the cell to complete the abscission of plant organs by feeling abscission signal of environmental factors and grow factor. The research progress of mechanism and regulation of hormones (auxin, ethylene and abscisic acid) and enzymes (pectinase, cellulose and peroxidase) in physiology and molecular was summarized in this paper. The conclusion may facilitate the study of constitutive model for the analysis on the mechanism and regulation of abscission of plant organs.