Abstract: In order to meet the needs of the watershed forest management practice in Liupan Mountains,based on the continuous forest inventory data from 120 fixed sample plots in this area,the law of watershed forest canopy density impact on the growth of the undergrowth shrub and herb was analyzed,the related mathematical models were established,and an objective stand vertical structure of watershed forests in the area was put forward in this study.The results show that,1)canopy density has impact on the growth of the undergrowth plant,the undergrowth shrub and herb coverage decrease with the increasing of canopy density;2)a distinct arbor-shrub-herb vertical structure can be formed when the canopy density is kept in the range of 0.5～0.8,and accordingly the relationship between ecological and economic functions will be well coordinated;3)the objective stand vertical structure in the area shows that the canopy density is kept in the range of 0.5～0.8,each shrub and herb coverage kept in the range of 35%～45%.Therefore,the result provides scientific support for the structure regulation of the watershed forest stands.

Key words: watershed forest, undergrowth plant, impact, objective stand vertical structure, structure regulation, Liupan Mountains