Abstract: This article is to understand the changes in leaf anatomy of Quercus aquifolioides in Sejila Mountain, Southeastern Tibet, and their environmental adaptability under different altitude gradients. Paraffin section method are used to determine anatomical features of leaves of Q. aquifolioides collected from 11 altitudinal gradients. The results showed that leaves of Q. aquifolioides are heterohedral, the upper epidermis has obvious cuticle, the lower epidermis has epidermis, and the palisade tissue cells have 2–3 layers; with the increase of altitude, the thickness of leaf, upper epidermis, lower epidermis, palisade tissue and spongy tissue increased, but tightness of leaf palisade tissue, looseness of leaf spongy tissue, midrib protrusion vein decreased; plasticity index analysis showed that Q. aquifolioides had lower plasticity in leaf anatomy, representing weak adaptability to the environment; correlation analysis of Q. aquifolioides showed that there was no significant difference between the thickness of palisade tissue and thickness of spongy tissue, between the looseness of leaf spongy tissue and tightness of leaf palisade tissue, but there was significant correlation between the other indexes.