Abstract: In this paper, the coordinate positions and crown breadth of plant individuals have been analyzed by using their fractal dimensions. The distributon patterns of population and population dynamic in the Quercus liaotunggensis forests at different altitudes are compared and discussed. The method of fractal analysis of simulation crown breadth is considered as a better method of studying spatial distribution of plant individuals with different and complex crown breadth. As altitude rises, the capacities of spatial occupation of different populations are variable. Q. liaotunggensis population maintains high level, with a fractal dimension reached 1.9811; Acer mono population go down with a fractal dimension is minimum, 0.1170. Whereas Abelia biflora population is strong at low altitude, Rhododendron micranthum population has stronger capacity of spatial occupation at high altitude. On the given environmental conditions, the capacity of spatial occupation of different populations become probably similar. However, the same fractal dimension between arbor and shrub layer implies different meaning. The fractal dimension of crown breadth, implying the capacity of spatial occupation of plant population, is one of the important indices in process of dynamic analysis and population distribution pattern.

Key words: fractal dimension, crown breadth, spatial occupation capacity, Quercus liaotunggensis