Objective: The anti-influenza virus activity of Galla Chinensis extracts was evaluated by an influenza virus neuraminidase (NA) inhibition assay. The constituents in the active extract were identified using ultra-high performance liquid coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) major constituents were used to further evaluate the NA inhibitory activity. Method: Using Neuraminidase Inhibitors Screen Kit to screen the four extracts of Galla Chinensis with anti-influenza virus activity. The chromatographic separation was performed on a C18 column with a gradient elution of methanol-aqueous formic acid 0.1%. The mass spectrometer equipped with electron spray ionization source was used as detector and the data was collected under the negative ion modes. Result: The results showed that four extracts of Galla Chinensis both presented NA inhibition activity. The ethyl acetate extract (EA) and the ethanol extract (E) presented strong. NA inhibitory activity with inhibition ratio of 69.64% and 78.24%

respectively. Eighteen constituents were characterized in these two active extracts by UPLC-Q-TOF-MS analysis

and three constituents (pentagalloyl glucose

ellagic acid

gallic acid) exhibited high activity against the influenza virus

IC50 values of 46.15

143.42

249.51 μmol ·L-1 respectively. Conclusion: Galla Chinensis has significant influenza virus neuraminidase inhibitory activity. Eighteen phenolic acids constituents were identified by UPLC-Q-TOF-MS. The results indicate that Galla Chinensis contains phenolic acids constituents as inhibitors of NA and provide a basis for anti-Influenza Virus Activity of Galla Chinensis study on its mechanism.