Abstract: In order to study the antibacterial mechanism of Amomum tsao-ko extract, the growth curve, protein content, broth conductivity were detected, including petroleum ether extract, chloroform extract, ethyl acetate extract, n-butanol extract after which were primarily separated.Chloroform extract, ethyl acetate extract minimum inhibitory concentration (MIC) were 1.25mg/mL, petroleum ether extract MIC was 2.5mg/mL, n-butanol extract MIC was 5mg/mL, under the action of Amomum tsao-ko extract MIC, the growth of Staphylococcus aureus OD value at each point was not obvious in the control group, the cell membrane permeability was increased, and protein content was slightly reduced, broth conductivity was improved.The study demonstrated that Amomum tsao-ko extract effectively inhibits the growth of Staphylococcus aureus, which maybe directly related to destruction of the Staphylococcus aureus membrane and cell wall.