Abstract: Samples of medicinal materials and decoction pieces of Lobelia Chinensis Lour from various regions in China were analyzed by HPLC to establish characteristic fingerprints of Lobelia Chinensis Lour, and 5 common peaks were identified as characteristic peaks of Lobelia Chinensis Lour. Among them, peak 1 was diosmin and peak 3 was linarin. The peak of linarin could be used as the reference peak. The characteristic fingerprints were fitted and modeled by orthogonal partial least squares-discriminant analysis,and the model was made successfully. Diosmin and linarin were found to be great contributions to the classification of medicinal materials and decoction pieces of Lobelia Chinensis Lour. Linear relationships between values of chromatographic peak area and mass of diosmin and linarin were kept in definite ranges, with detection limits (3S/N) of 0.030 4, 0.031 8 mg·L^-1 respectively. Values of recovery of diosmin and linarin found by standard addition method were 97.7%, 100% respectively, and values of RSDs (n=6) of determined values were 1.3%, 2.5% respectively. The proposed method was applied to the analysis of samples of medicinal materials and decoction pieces of Lobelia Chinensis Lour. The contents of diosmin and linarin in medicinal materials were higher than those in decoction pieces.