Abstract: In the paper, the research object was Abies georgei var.smithii that distributes in Sejila mountain of Tibet. For the research,fifteen 30m×30m plots were set up and the contiguous grid quadrats applied to sampling for field data. The population characteristics were analyzed including height structure, basal diameter structure, age structure and spatial pattern. The results indicated that three structures of A. georgei population manifested as the anti-"J" type, the correlation was obvious, the relationship of basal diameter and age was y=13.5640x^0.7078 (R²=0.9144), seedlings backup reserved particularly large, the death rate was high, but the supplemental rate was higher than the death rate and the population was steady. Under different scales, the spatial patterns of different age-class (developmental stage) plant were different. With the sampling scale increasing, the spatial patterns of different age-class plants were clumped distribution pattern, but tended to be uniform distribution pattern, the degrees of intensity were decreasing from high to low, the same sampling scale, the greater the age class, the weaker the intensity. The research results provided the theoretical basis for management and sustainable utilization of A. georgei.

Key words: Abies georgei var.smithii, population structure, spatial pattern