Abstract:To explore the law of leaf color change of Davidia involucrata, we selected pink D. involucrata (pink bracts and leaves) and common D. involucrata (green leaves and white bracts) to compare the anatomical structure and pigment content. The results showed that: (1) two colors of D. involucrata leaves were bifacial leaf, containing a palisade tissue with onelayer neatly arranged long columnar cells and a loosely arranged sponge tissue. The upper epidermal cells of some pink leaves bulged outward, and the total thickness, cuticle, palisade tissue and sponge tissue of the pink were thicker than those of green ones, while the epidermis was thinner. (2) There was no differentiation between palisade tissue and sponge tissue in two D. involucrata bracts. The upper epidermal cells of the pink bracts bulged significantly with the thickening of the cuticle, while the lower epidermis became thinner. (3) The contents of flavonoid and anthocyanin in pink leaves were 1.52 times and 3.67 times that of green leaves. The difference of photosynthetic pigment content between two leaves was not obvious, but the chlorophyll a/b value of pink leaves was significantly lower. The anthocyanin content of pink bracts was significantly higher than that of white bracts, while the flavonoid content of the two was not much different. In conclusion, anthocyanin directly caused D. involucrata leaves and bracts to turn pink, and flavonoid helped the leaves appear pink. The anatomical structure of pink D. involucrata leaves and bracts had changed, which had the higher light energy utilization efficiency and were more suitable for the wet environment.