Erigeron breviscapus and erigeron multiradiatus,belonging to compositae, have been widely used as “meiduoluomi” in traditional Tibetan medicine for treatment of heat clearing and detoxicating. However, it is difficult to distinguish them because of similarity of morphology. Therefore, the chemotaxonomy method was established. FTIR fingerprint spectra of E. breviscapus and E. multiradiatus samples from 13 geographical origins were studied. The results demonstrated that theycould be divided into 2 classes with prin cipalcomponent analysis(PCA). The classification was well correlated to their gene, geographical origins and weather. In the same class, thechemical components are similar to each other, which can be considered as thecriterion for evaluating their quality. Theresults showed that their infrared spectra characteristic of the same species was similar in the range of 4000-450 cm ^-1, but varied significantly for different species. The method is rapid and simple, and could be applied to evalu ate the quality of this traditional medicine.