This study compared the compositional differences of five peony roots in the processing process:moutan bark,moutan bark removed cork,cork,root core and fibrous root,explores the scientificity of the medicinal parts of peony,and evaluates the value of the development and utilization of the non medicinal parts of the root of peony.The characteristic chromatograms of different parts of peony root were established by ultra-high performance liquid chromatography.The chemical components in different parts of peony root were analyzed by pattern recognition techniques such as hierarchical clustering analysis (HCA),principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) in chemometrics.Seven of the ten differential components selected can be identified and the chemical components with content greater than 0.1 mg/g are used as quantitative analysis indicators for component content determination.The chemical constituents of moutan bark,moutan bark removed cork and fibrous root were similar by characteristic chromatogram and chemometrics analysis;The chemical constituents of the root core and cork were significantly different from the first three.The chemical constituents in the root core were less and the content was lower;The chemical constituents of cork are the most abundant,and monoterpenes and glycosides account for a large proportion.This study shows that there is no significant difference in the principal components between moutan bark,moutan bark removed cork and cork,which provided a basis for the processing of Moutan Cortex in the producing area to leave cork and remove root core;The fibrous root and root core of peony also have certain medicinal value,which can be considered for comprehensive development and utilization.