Abstract: Since the Tertiary period, Quercus liaotungensis which were affected several times by cold, warm, dry and wet climatic variations, has displayed eurytopic characteristic in climate, it is the basis on which was formed the modern distribution range. This type of forest may occur as zonal vegetation in loess district near steppe zone or vegetation of vertical zone on Qinling mountain. The Quercus liaotungensis forests of Qinling are more complex than that of loess district in the floristic component, stratification and structure of synusia as well as ecological type etc. From now on, Quercus liaotungensis forests in present area on Qinling mountains and loess plateau are still one of the stablest plant communities.