Zhaxun is usually divided into four grades. Zhaxun is of better quality with black color, heavy quality and fewer feces, according to the experience of traditional Tibetan medicine. Different grades have little difference in appearance, and it is more difficult to distinguish after boiling into pastes. Fourier transform infrared spectroscopy(FTIR) has the advantages of being fast, and nondestructive and has been widely used in medicinal material identification. They were exploring the feasibility of FTIR to identify Zhaxun of different grades with FTIR. 56 batches of medicinal materials and substitutes were collected and divided into four grades according to the proportion of feces and morphology. Each batch was processed into dry pastes according to the Tibetan medicine standard of six provinces. Different chemopmetric methods established models according to different samples in the range of 4 000～400 cm-1. Preconditioning methods contain Saitzky-Golay (S-G) smoothing, ordinate normalization, and second derivative transformation for preprocessing, and the main absorption regions of Zhaxun are 3 500～3 200, 3 000～2 800, 1 800～1 350, 1 350～900, 900～400 cm-1. There are great differences in the indices of the absorption peaks of substitutes. Only Zhaxun of grade Ⅰ and grade Ⅱ have absorption peaks near 1 779 cm-1. The intensity of Zhaxun of grade Ⅰ and grade Ⅱ near 1 768 cm-1 is significantly stronger than grade Ⅲ and substitutes. Only substitutes near 1 660 cm-1 have no absorption peak, and substitutes at 1 257 cm-1 have an absorption peak. These can be used as the identification of Zhaxun’s different grades. Changes absorption peaks in area ③ and area ⑦ are related to the traditional classification that the stronger peak intensity is related to quality. Principal Component Analysis (PCA) is difficult to distinguish Zhaxun of different grades. However, Partial Least Squares Discriminant Analysis (PLS-DA) can better distinguish medicinal materials of four grades and results of external verification show that the model can well distinguish Zhaxun of different grades according to the statistical chart of results of SIMCA. The hierarchical cluster method(HCA) can distinguish some batches of Zhaxun of grade Ⅲ and substitutes through SPSS21.0. FTIR combined with chemometrics provides a rapid method for the quality evaluation of Zhaxun that can quickly identify the grades of Zhaxun and distinguish the substitutes.