Analysis of the similarity and difference of volatile oil components of Plantaginis Herba from different sources.The volatile oils of 14 batches of Plantaginis Herba were extracted by hydrodistillation,and the chemical components of the peaks were separated and identified by gas chromatography-mass spectrometry (GC-MS).The volatile oil fingerprints of the samples were introduced into the fingerprint similarity evaluation system,and the similarity was obtained by multi-point calibration using Plantago depressa Willd. P1 as the reference spectrum.The results of volatile oil detection of 14 batches of samples were analyzed by using cluster analysis (HCA),principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA).The results showed that 62 chemical components and nine common components were identified from the volatile oil of 14 batches of samples,and palmitic acid,linoleic acid and α-linolenic acid were the main components.The fingerprint profiles of 14 batches of samples were highly similar,with the similarity ranging from 0.967 to 0.999.Neither HCA nor PCA could classify two different sources Plantaginis Herba species into two categories.The above results indicated that the volatile oil components of Plantago asiatica L. and Plantago depressa Willd. were highly similar,and their inclusion as the same herb had a certain scientific basis.