Abstract: In order to reveal the formation reasons for different colors of ornamental Eucommia leaf, the leaves of Eucommia ulmoides ‘Hongye’, E. ulmoides ‘Miye’ and E. ulmoides ‘Xiaoye’ were studied by using freehand section combined with photosynthetic pigments and anthocyanin content measurement. The results showed that for E. ulmoides ‘Hongye’, the front of the blade was dark red while the back was green, the pigment causing redness concentrates on the leaf palisade tissue; among the three varieties, Ca was 1.100 3~1.314 8 mg·g-1, Cb was 0.435 4~0.467 0 mg·g-1, CCar was 0.384 7~0.445 5 mg·g-1, CT was 1.462 5~1.781 8 mg·g-1, CF was 0.140 8~0.304 2 mg·g-1, CCar and CF of E. ulmoides ‘Hongye’ were significantly higher than that of E. ulmoides ‘Miye’ and E. ulmoides ‘Xiaoye’, while CT/CCar was significantly lower than E. ulmoides ‘Miye’ and E. ulmoides ‘Xiaoye’, moreover, the Ca, Cb, Ca/Cb and CT showed no significant difference between E. ulmoides. ‘Hongye’ and E. ulmoides ‘Miye’. The conclusion in this study stated that the anthocyanin and carotenoids contents were higher, which was the main reason for forming red color of E. ulmoides ‘Hongye’.