In order to explore the trait indicators to evaluate the quality of Gentianae Radix et Rhizoma,the correlation between Gentianae Radix et Rhizoma and the main active ingredients was explored.Vernier calipers,hardness testers,colorimeters,electronic tongues and high-performance liquid chromatography (HPLC) were used to determine Gentianae Radix et Rhizoma root length,apical diameter,middle diameter,terminal diameter,fibrous root number,hardness,surface section chromaticity value,bitterness value and the content of five iridoid terpenoids,and the correlation analysis,regression analysis and principal component analysis (PCA) were carried out on the trait indexes and component contents.Orthogonal partial least squares-discriminant analysis (OPLS-DA) and cluster analysis.The results of SPSS 22.0 correlation showed that Gentianae Radix et Rhizoma root length,hardness,upper diameter,middle diameter,surface brightness L^*₁,color difference value E^*ab₁ and bitterness value were significantly correlated with the contents of loganic acid,swertiamarin and gentiopicroside in Gentianae Radix et Rhizoma,indicating that the longer the Gentianae Radix et Rhizoma root,the greater the hardness,the thicker the diameter of the upper and middle ends,the lighter the epidermis and the more bitter the taste,the higher the contents of loganic acid,swertiamarin and gentiopicroside.The 32 batches of Gentianae Radix et Rhizoma were divided into three grades by K-means clustering method,and limited identification was achieved by OPLS-DA model,and there were significant differences in Gentianae Radix et Rhizoma content among the grades.The traits of Gentianae Radix et Rhizoma (root length,hardness,tip diameter,middle diameter,surface brightness L^*₁,color difference value E^*ab₁,bitterness value) can be used as the basis for evaluating the quality of Gentianae Radix et Rhizoma,and the traditional record of Gentianae Radix et Rhizoma "thick roots,yellow or brownish-yellow,yellowish-white cross-section,and extremely bitter Gentianae Radix et Rhizoma" have been proven.Therefore,the quality of Gentianae Radix et Rhizoma can be judged according to its characteristics,which provides a basis and theoretical basis for the establishment of objective and scientific evaluation of the quality of Gentianae Radix et Rhizoma.