Abstract: OBJECTIVE To analyze and identify water-soluble composition and alcohol-soluble composition in Cornus officinalis. METHODS These constituents were determined by UPLC-ESI-Q-TOF-MS. The chromatographic separation was performed on ACQUITY UPLC HSS T3 C₁₈ (2.1 mm×100 mm, 1.8 μm) with a gradient elution of water containing 0.2% formic acid-methanol containing 0.2% formic acid. The mass spectrometer equipped with electrospray ionization source was used as a detector. And data was collected under the positive and negative ion modes. RESULTS Five water-soluble constituents were identified as gallic acid, morroniside, loganin, cornuside Ⅰ, sweroside. And five alcohol-soluble constituents were identified as 7-dehydrologanin, cornuside Ⅱ, quercetin, oleanolic acid, ursolic acid. CONCLUSION In this study, water-soluble and alcohol-soluble constitutents in Cornus officinalis were separated by UPLC, and identified through the information of positive ion and negative ion and accurate MW(molecular weight) which were determined by UPLC-ESI-Q-TOF-MS. It is an accurate and effective method which can be applied for the constituent identification of Cornus officinalis.