The Coreopsis oleoresin essential oil was extracted by supercritical CO 2 fluid,and the components were separated and identified by the gas chromatography mass spectrometry( GC-MS) technology. The results showed that 84 compounds in the essential oil from Coreopsis oleoresins were identified,and the main compounds amounted to 92. 16 % of their total compounds were olefins( 64. 12%),alcohols( 11. 47%),alkenes( 8. 76%),acids( 6. 31%),and esters( 1. 5%) which. The bacteriostatic circle and minimum inhibitory concentrations( MIC) was taken as the index for investigation. The antibacterial activity was evaluated by filter paper method. The results showed that Coreopsis oleoresin essential oil had significant inhibition effect on general fungi and bacteria. The minimum inhibitory concentration( MIC) on E. coli was 25%,and on Staphylococcus aureus,Bacillus subtilis,Penicilliumthe,Aspergillus niger were 50%,75%,50%,75%,respectively.