In order to identify the basic source of Hedyotis diffusa in Puer Duanwu Medicine market, the herbs of Hedyotis diffusa were collected by visiting the Duanwu medicine market in Puer. The plant source was determined by observing the stem, leaf shape, inflorescence type and growth position of the original plants and herbs, the shape of capsules and the presence, length and thickness of fruit stalks. There were 3 kinds of "Hedyotis diffusa" sold in Puer Duanwu medicine market. They are Hedyotis diffusa Willd, Hedyotis tenelliflora Blume and Hedyotis corymbosa(L.) Lam. Through literature search, the medicinal progress of the three plants was compared. The chemical composition and pharmacological action of the three plants were different, and attention should be paid to differentiation when using to ensure the safety of clinical drug use.