Abstract:The leaf anatomical structure of Nitraria tangutorum Bobr.from three natural populations(WMX,ZGL,JGC) of different habitats along Hexi corridor were researched.The leaves were anatomically observed,and indexes including leaf length,width and thickness,upper and lower pubescence length,width and density,upper and lower stoma length,width,area and density,upper and lower cuticle thickness,upper and lower epidermal cell thickness,palisade tissue thickness,spongy tissue thickness,diameter of main vein,diameter of lateral vein,diameter of crystal cell,mucilage cell length,width and aqueous tissue length,width were measured.At the same time,the ratio of palisade tissue thickness to spongy tissue thickness (P/S),tightness (CTR) and looseness of leaf tissue structure were statistically analyzed.The differences of one index among three populations were compared to explore the adaptive response mechanism of leaf morphology anatomy features to different habitats.The results are as follows:(1)The indexes had different degrees of differences except some indexes including leaf length,width,ratio of length to width and lower pubescence width,the indexes such as leaf thickness and area,upper and lower pubescence length and density,upper and lower stoma length and density,upper epidermal cell thickness,upper and lower palisade tissue thickness,spongy tissue thickness,but P/S,CTR,diameter of vascular bundle,mucilage cell length and width all had significant differences among three populations.(2)The rank of variation coefficients and plasticity indices of aggregative indicators from three populations were the same,the order was JGC>WMX>ZGL.It showed that the ecological adaptability of N.tangutorum Bobr.was JGC>WMX>ZGL.(3)The plasticity indices of palisade tissue,spongy tissue,pubescence,cuticle of N.tangutorum Bobr.from three populations were relatively high.These organizations played a dominant role in response to different environment.The results above may be the adaptive response mechanism of leaf anatomical characteristics to different habitat conditions.