Abstract: The position and process of balsamic duct formation and the influence of serial cutting on the secreting ability of balsamic duct of Styrax hypoglauca Perk. were studied. The results showed that: (1) there is neither secretory tissue nor balsamic secretion in the normal trunk of the tree, wound balsamic ducts are formed only after the trunk is injured; (2)the balsamic ducts are formed schizo-lysigenously from the parenchymatous cells near the vascular cambium; (3) the operation of serial cutting not only increases the strength of stimulus but also promotes the formation of new balsamic ducts; (4) the application of ethrel promotes the process of balsamic duct formation and, under serial cuttings, the wounds were prevented from recovery, so that the latent capacity of balsamic production of the ducts can be brought into full play; (5) turgot pressure, which can be increased by treatment of ethrel, is an indication of the ability of balsamic production of the tree.