Abstract: One and three-year-old Emmenopterys henryi Oliv. seedlings were used to explore the effects of weak light on the stomata characteristic and anatomical structure of leaves under full light (L100), 40% full light (L40), and 10% full light(L10). Results showed that the stomatal density and percentage of stomatal apparatus area of one and three-year-old seedlings decreased with the decrease of light intensity. Under L40, the stomatal length, stomatal length/stomatal width, individual stomatal area, and stomatal opening of one-year-old seedlings are the highest, while the stomatal length, stomatal length/stomatal width, area of a single stoma, and stomatal opening of three-year-old seedlings are the lowest. Under L100, the stomatal length, stomatal width, area of a single stoma, stomatal opening, the net photosynthetic rate of one-year-old seedlings are lower than those of three-year-old seedlings. Under L40, the stomatal length, stomatal length/stomatal width, area of a single stoma, and stomatal opening of one-year-old seedlings were higher than those of 3-year-old seedlings. In one or three-year-old seedlings, the leaf thickness, lower epidermal thickness, palisade tissue thickness, sponge tissue thickness, palisade tissue thickness/sponge tissue thickness, stratum corneum thickness and leaf tissue structure compactness depressed with the increase of shade. Under full light, the the leaf thickness, lower epidermal thickness, palisade tissue thickness, sponge tissue thickness, palisade tissue thickness/sponge tissue thickness and leaf tissue structure compactness of one-year-old seedlings were clearly higher than those of three-year-old seedling. In one-year-old seedling, the palisade tissue thickness/sponge tissue thickness was higher while the sponge tissue thickness and stratum corneum thickness were lower than those in three-year-old seedling under L40. Under L10, the palisade tissue thickness, palisade tissue thickness/sponge tissue thickness, and leaf tissue structure compactness of one-year-old seedlings were higher than those of three-year-old trees. As the light intensity decreased, the radial width of the xylem, diameter of xylem vessels, and diameter of vein bundles decreased whereas the main vein protrusion degree increased in one or three-year-old seedlings. The number of single vessels changed little. The thickness of the main vein of one-year old seedlings under L40 treatment was higher than that of the control but the the main vein of three-year-old seedlings dropped with reduction of light intensity. The the radial width of the xylem, single vessels, diameter of vein bundles, and the main vein of one-year-old seedlings were higher than those of three-year-old seedlings. However, there was no significant difference in diameter of xylem vessels. In a word, one and three-year-old seedlings responded differentially to the change of environmental light intensity.