Abstract: In order to clarify the influence of the traditional processing on the chemical constitution of Scrophulariae Radix, the UPLC-Q-TOF MS method was used to analyze the dried and processed Scrophulariae Radix. Data were processed by principal component analysis (PCA) and orthogonal partial least squared discriminant analysis (OPLS-DA) to find the difference between dried and processed Scrophulariae Radix. The accurate m/z values of Q-TOF MS and Q-TOF MS/MS fragments were applied to constitution identification. The results show that a total of 26 constituents have significant differences between dried and processed Scrophulariae Radix. Fifteen constituents are identified, including 9 iridoid glycosidesand 6 phenylpropanoid glycosides. Compared with the dried Scrophulariae Radix, the contents of aucubin, 6-O-methylcatapol, harpagoside, 8-O-cumaroylharpagide, 8-O-feruloylharpagide, acteoside, isoacteoside, angoroside C and scrophuloside B₁ in processed Scrophulariae Radixwere are decreasing. The contents of harpagide, harp agoside isomer, 6″-O-α-D-galactopyranosylharp agoside, 6-O-α-D-galactopyranosylharp agoside, sibirioside A and cinnamic acid are increasing. In Scrophulariae Radix, scrophuloside B₁ is detected for the first time. The UPLC/Q-TOF-MS method proves to have a high sensitivity and the result isaccurate and reliable. The method could fully reflect the changes of multiple chemical constituents in the course of processing and lay a good foundation for the further study of processing mechanism of traditional Chinese medicine.