Abstract: In order to study the variation of morphologic traits and influencing factors of natural populations of Quercus liaotungensis Koidz.in Lingkong Mountain Nature Reserve of Shanxi Province, 5 populations were sampled, and 24 morphologic traits of leaf and apical bud were investigated.The variance analysis shows that variations of all the morphologic traits within population are significant, and significant differences exist in 5 character indices among populations(α=0.05) which may result from genetic and environmental factors.The results reveal that direction and degree of slope average DBH in populations and population density are main influencing factors.Intrapopulation variation mainly contributes to morphologic variation, and the phenotypic differentiation coefficient is 13.31%, which indicates a low level of differentiation.But several characters exhibit a high differentiation level such as the tooth width of leaf base(25.99%) and the width of middle apical bud(25.23%).The morphologic indices including the tooth of leaf base, leaf tip, petiole and leaf area vary greatly within population which may arise from the variation of individual development.However, only two morphologic indices, the middle apical bud and the tooth of leaf base, are unstable, which indicates the extensive influence of environmental factors.