Abstract: The population dynamics of major species in a Quercus liaotungensis forest in the Dongling Mountain region, northern China was described based on data from a permanent plot (30 m×40 m) collected over an 11-year period. The age of this forest is about 80 years. The total density of all trees >2 m in height decreased from 1 658 trees•hm-2 (1991), to 1 442 trees•hm-2 (1997) and to 1 400 trees•hm-2 (2002). This decrease in density was mainly due to the death of Q. liaotungensis individuals, which accounted for ca. 75.88%, 72.82% and 67.86% of total density in 1991, 1997 and 2002, respectively. The total basal area increased from 23.48 m2•hm-2 to 27.38 m2•hm-2 over the 11 years, reflecting the growth of surviving individuals. Despite a lack of saplings and new recruits, the Q. liaotungensis had an abundant population of adult trees and exhibited a unimodal size distribution in all three investigations (1991, 1997 and 2002) with no significant differences between them. The patterns of growth, mortality and competition in the Q. liaotungensis population were investigated for individuals>2 m in height, based on the diffusion model. The mortality rate curve, M(t,x), was inverse J-shaped and decreased significantly with DBH up to 10 cm, indicating size-dependent mortality. The mean value of absolute growth rates, G(t,x), was linearly correlated with DBH. The analysis of coefficients in the model and concave relationship of G(t,x) - D(t, x) in Q. liaotungensis population suggested asymmetric intraspecific competition, mainly for the limited light resource due to the relatively high density of the forest. Asymmetric competition might act as a structuring force to maintain the stability of Q. liaotungensis populations and community dynamics.