Abstract: Using paraffin section and scanning electron microscope, the leaf anatomical structure were investigated in Rhododendron obtusum（Lindl.） Planch. cv. Yanzhimi, R. obtusum cv. Huahudie and R. obtusum cv. Xishi under drought stress in light incubator. The results showed that the stomata only distributed in the lower epidermis and there were epidermal hair and trichome on both upper and lower epidermis. With heavier drought stress, the width of stomata became smaller and then the stomata closed in the later period. The leaf was thinner and the ratio of the palisade tissue to spongy tissue increased after drought stress. The change of ratio of palisade tissue to spongy tissue was the largest, and the time of stomata closure was relatively later in R. obtusum cv. Yanzhimi with relatively highest drought resistance. There is an important association between leaf anatomical structure and drought resistance in Rhododendron.

Key words: Rhododendron obtusum（Lindl.） Planch., drought stress, drought resistance, leaf anatomical structure, scanning electron microscope （SEM）