Abstract:Random amplified polymorphic DNA(RAPD) and DNA amplification fingerprinting (DAF) markers were used in detecting genetic structure and DNA diversity of two Liaodong oak ( Quercus liaotungensis Koidz. ) populations at Dongling mountain region, a suburb of Beijing City. Shannon‘s index of phenotypic diversity was used to partition diversity into components within and between populations. Two hundred and five bands from twelve primers were analyzed. The results showed very high genetic variability within the Liaodong oak populations. The diversity in the central population was higher than that of the marginal one. 95 % of total genetic diversity occurred within populations and the coefficient of gene differentiation was 0.05. Significant difference of gene frequency has been detected in a few loci between populations. The study of different age groups of the oak trees implied that deforestation exerted certain impacts on the genetic structure of the Liaodong oak.