An ultra-performance liquid chromatography－quadrupole time-of-flight mass spectrometry（UPLC－Q－TOF MS） was applied to construct the fingerprints of raw Fingered Citron and processed Fingered Citron. Meanwhile，the chemical components differences between raw Fingered Citron and processed Fingered Citron were analyzed by chemical pattern recognition methods．The sample was firstly ultrasonically extracted with methanol，and then separated on an Agilent Poroshell 120 EC－C,18,（3.0 mm × 150 mm，2.7 μm） column by gradient elution，with 0.1% formic acid + 5 mmol/L ammonium acetate and acetonitrile as the mobile phases．The MS system with electrospray ionization（ESI） source was operated under positive and negative ion mode．Based on the accurate mass， fragment ions， retention behaviors， previous reports，net-work database and the fragmentation pathways，a total of 37 components in the raw Fingered Citron and the processed Fingered Citron were identified，including 10 flavonoids and flavonoid glycosides，4 coumarins，12 organic acids，5 glycosides，2 limonin and 4 other compounds．The fingerprints for the two Fingered Citrons were established，and analyzed by a similar evaluation system for chromatographic fingerprint of traditional Chinese medicine（version 2004 A，National Committee of Pharmacopoeia，China）．The mass of each peak was accurately measured，and their chemical formula were generated via the MassHunter software．The MS/MS spectrum for each peak was compared with the mass database and literature，and their chemical structures were deduced based on the MS/MS fragment，and finally verified by the reference substance．In total，the UPLC－Q－TOF MS fingerprint for raw Fingered Citron contained 24 common peaks，of which 19 were identified. In addition，there were 22 common peaks in the UPLC－Q－TOF MS fingerprint for processed Fingered Citron，and 14 peaks were identified．The principal component analysis（PCA） and orthogonal partial－least squares discriminant analysis（OPLS－DA） were adopted to analyze these data of two herbal medicines via SIMCA－P software（pretreatment with Profinder software）．The results of PCA and OPLS－DA showed that the two Fingered Citrons were significantly discriminated．Nomilin acid，5-isopentenyloxy-7-methoxycoumarin，palmitic acid，oleic acid and oxypeucedanin hydrate were identified，and screened as the chemical markers that attributed to classification. Among them，the content of 5-isopentenyloxy-7-methoxycoumarin changed prominently，and was chosen as the chemical marker for differentiation on raw Fingered Citron and processed Fingered Citron．This study provides a data support for the quality control of raw Fingered Citron and processed Fingered Citron.