Chelidonium majus is a perennial herb with a plant height of 40 ~ 90 cm. After the plant is broken, red and yellow milk flows out. The taproot is stout, conical, khaki or dark brown with many fibrous roots. The stems are erect, multi-branched, tender green, covered with white powder, and the whole plant is sparsely white villous. Leaves alternate, 1 ~ 2 pinnate, the basal leaves are large, with 5 ~ 8 pairs of leaflets, which gradually decrease from top to bottom, the top leaflets are broadly obovate, the upper part is 3-lobed, and each lobe is 2 ~ 3-lobed. The base wedge extends downward and finally connects with the bases of the two leaflets. Cauline leaves are small, with irregular edges, 3-4 pairs of leaflets, upper green and lower pink, and 2-4 pairs of whole lobes. Umbellies terminal or axillary, with 2 sepals, elliptic and caducous. Petals, yellow, obovate or long obovate; Stamens are numerous. Ovary strip glabrous, 2 carpels, short style, capitate stigma. The capsule is long and cylindrical, and cracks upward from the base when it matures. The seeds are small, ovoid, mostly dark brown, shiny and reticulate when mature. The flowering period is from May to July, and the fruiting period is from June to September.