Thistle is divided into Cirsium japonicum and Cirsium japonicum. Cirsium japonicum, with feathery leaves, prickly edges, plump roots and purplish red flowers, belongs to the same family and different genera, with similar properties, and is used as medicine. Sweet, cool and nontoxic. Cirsium japonicum contains volatile oil, alkaloid, resin, inulin and cyanoside; The whole plant of Cirsium japonicum contains alkaloids, saponins and so on. Thistle has antibacterial effect.