To screen new biological activities of hawthorn seeds and explain its material basis of pharmacodynamics.Methods:By measuring the minimum inhibitory concentration(MIC)，the DPPH，ABTS radical scavenging rate and Fe3+ reducing ability were evaluated，and the antibacterial and antioxidant activities of the ethanol extract and different polar solvent extracts of hawthorn seeds were investigated，and the active fraction was obtained.Then，the chemical constituents of the active fraction was analyzed by Ultra performance liquid chromatography tandem time of flight mass spectrometry(UPLC-Q-TOF/MS).Results:The ethyl acetate extraction part is the active fraction of hawthorn seed for anti-bacterial and anti-oxidative.A total of 21 chemical components were inferred from the active fraction by LC-MS/MS analysis，including 16 lignans，3 phenylpropanoids and 2 flavonoids.Conclusion:Lignans are the main medicinal effective ingredients of hawthorn seeds and deserve in-depth study.