Meisona chinensis Benth.,a characteristic herb of south of China,is known as “Immortal herb” because of its excellent functions of heat elimination,heat clearing,detoxification and so on.Ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass/mass spectrometry (UPLC-Q-TOF-MS) was selected for the study.A BEH C₁₈ column (2.1 mm × 100 mm,1.7 μm) was used with the mobile phase of eluent (A) MeCN containing 0.1% formic acid and eluent B 0.1% formic acid in water.Q-TOF-MS and electrospray ion (ESI) source were applied for the analysis under the negative ions.Fifty-one compounds were identified including 40 polyphenols,3 terpenoids,and 8 other compounds,whereas 1 phenylpropionic acids,1 lignan dimers,2 lignan trimmers,3 flavonoids and 3 terpenoids were firstly identified in Meisona chinensis Benth.