We implemented typical sampling method,in order to illustrate the crown architectural variation of Quercus liaotungensis saplings in different habitats and understand the response and adaptation mechanisms of plant to different environment conditions.The characteristics of lateral branch and leaf,as well as their spatial distribution for Q.liaotungensis saplings,which grew in three different habitats (under story,forest gap and forest edge) in Huanglong mountain of Loess Plateau,were investigated.The results showed that:(1)the crown morphological features of Q.liaotungensis saplings changed in response to three kinds of habitats,the crown of understory is simple and the crown of the other habitats are rich.(2)The tree height and the height under branch declined and the diameter increased from understory,forest gap to forest edge.The crown width,crown area,crown ratio of the saplings increased first and then decreased,and the variance under 3 habitats is significant.Overall bifurcation ratio,gradually branching ratio,branch diameter ratio of saplings firstly increased then decreased from understory,gaps to forest edge.(3)Under three kinds of habitats,the length,diameter and angle declined with the tree height increased,and the variance is not significant.The firstolder branches were mainly in the top area of the canopy and in the other two habitats were mainly in the middle of the canopy.(4)Leaf length,leaf width,leaf area and leaf area ratio decreased,while the average leaf number,total leaf area and LAI firstly increased and then decreased,from understory,gaps to forest edge.Compared with the other two habitats,the leaves of understory were mainly in the top of the canopy.(5)Aboveground biomass of saplings,the trunk biomass of understory accounted for 83%,branch and leaf biomass account for only 17%.Under the gaps and forest edge habitats,the biomass of various parts was different,but the proportion was basically the same.The biomass of trunk accounted for 66%,and biomass of branch and leaf accounted for about 34%.Under three habitats,the sapling architecture of forest gap was better than that of the other two habitats.In the future,appropriate thinning techniques should be used to increase the number of the forest gap and provide favorable conditions for regeneration and structure optimization of Q.liaotungensis forests.