Objective: In order to make clear the components of the essential oil from the aerial part of Bupleurum chinense DC. f. vanheurckii (Muell.-Arg.) Shan et Y.Li and the antimicrobial activities. Method: Distillation in water vapor was applied to extract the essentialoil from B. chinense and meanwhile GC-MS was used to analyze the components of this plant. Its antimicrobial activities were investigated by plate diffuse and the minimum inhibitory concentration (MIC) was investigated by plate spread. Result: The essential oil was extracted successfully and 30 compounds were identified. Meanwhile the antimicrobial activities were tested and a broad-spectrum antimicrobial activity of the essential oil was found. Conclusion: Main components of the essential oil from B. chinense areterpenes and low molecular aliphatic hydrocarbon compounds. And the antimicrobial intensity to the tested strains is: Staphylococus aureus>Penicillium citrinum>Escherichia coil>Staphylococcus albus>Bacillus subtilis>Aspergillus niger>Aspergillus flavus.