Abstract: Objective: To establish an infrared fingerprint of Swertia mileensis, and provide a reference for its quality control. Methods: 20 batches of Swertia mileensis were collected from different production areas, Fourier transform infrared spectrometer was used to establish their infrared fingerprints, and similarity analysis, cluster analysis and principal component analysis were conducted to compare the differences in the composition of Swertia mileensis from the production areas. Results: A total of 11 common characteristic absorption peaks were identified in 8 batches of control Swertia mileensis, which were 3 364.8, 2 926.2, 1 611.5, 1 518.2, 1 418.8,1 324.1, 1 262.3, 1 071.2, 895.1, 839.4, 655.1 cm-1. The second derivative, principal component analysis and systematic clustering analysis can all be used to identify Swertia mileensis from similar medicine. Conclusion: This method is precise, has good repeatability and stability, and can be used for rapid identification for Swertia mileensis.

Key words: Swertia mileensis, similar medicinal materials, infrared fingerprint, principal component analysis, cluster analysis;
identification