Abstract: OBJECTIVE To Establish a liquid chromatography-mass spectrometry analysis method to comprehensively and quickly identify the chemical components in Gleditsiae Fructus Abnormalis. METHODS The ultra-high liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry(UHPLC-Q-TOF-MS/MS) was applied for the composition analysis of Gleditsiae Fructus Abnormalis extract; its mobile phase was 0.1% formic acid(A)-acetonitrile(B) with gradient elution at a flow rate of 0.3 mL·min^-1. Accurate ion mass and secondary fragmentation information were obtained in negative ion mode, combined with databases and standard reference for structure elucidation. RESULTS A total of 78 compounds(32 flavonoids, 15 phenolic acids, 22 lignans and 9 chemical constituents of monoterpenoid acids) with 14 potential new compounds were screened. CONCLUSION This study comprehensively analyzes the chemical composition of Gleditsiae Fructus Abnormalis, and provides a basis for the investigation of the pharmacodynamic basis and quality standards of this drug.