An ultra performance liquid chromatography-quadrupole time of flight mass spectrometric(UPLC-Q-TOF-MS) method was established for the identification of chemical constituents in the extract of Eurycoma longifolia Jack.The sample was separated on an Agilent Eclipse Plus-C18 RRHD(2.1 mm×100 mm,1.8 μm) column with acetonitrile and 0.1% formic acid water as mobile phases by gradient elution.The data were collected with electrospray ionization in positive mode.According to the contrast of the reference standards and the accurate masses of molecules,a total of 49 compounds in Eurycoma longifolia Jack extract were identified,including 29 quassinoid diterpenoids,4β-carboline alkaloids,12 canthin-6-one alkaloids,3 biphenyl-neolignans and 1 squalene triterpene.The method was accurate,reliable and efficient,and could comprehensively reflect the chemical constituents of Eurycoma longifolia Jack,and provided a reference for further elucidating its pharmacological basis and quality controll.