Abstract: Objective:The purpose of this experiment was to determine the chemical constituents of Zanthoxylum bungeanum aromatic oil from Longnan Dahongpao,Gansu Province,and its bacteriostatic effect on four bacteria:Escherichia coli,Staphylococcus aureus,Nicolaieri's bacillus and Pseudomonas fluorescens. Methods:The aromatic oil from Zanthoxylum bungeanum L. in Longnan Dahongpao was extracted by steam distillation. The components were analyzed and identified by gas chromatography-mass spectrometry(GC-MS). The antimicrobial activity of the aromatic oil from Zanthoxylum bungeanum L. in Longnan Dahongpao was studied. Results:An amount of 50 chemical constituents were identified in the aromatic oils of Zanthoxylum bungeanum in Dahongpao,Longnan,accounting for 92.49% of the total. The main chemical constituents included D-limonene(32.08%),dextrocarvone(20.02%)and a-humulene(12.26%). The results showed that the aromatic oil of Zanthoxylum bungeanum had bacteriostatic activity against four kinds of bacteria.Among them,the antibacterial effect of Staphylococcus aureus and Pseudomonas fluorescens was better. The minimum inhibitory concentration(MIC)and minimum bactericidal concentration(MBC)were 2.5 and 5.0 mL/L,respectively. Conclusion:The chemical constituents of the aromatic oil of Zanthoxylum bungeanum from Longnan Dahongpao in Gansu Province were determined,and the minimum inhibitory concentration and bactericidal concentration of the essential oil of Zanthoxylum bungeanum for E.coli,S. aureus,N. bacillus and P. fluorescens were obtained,which laid a theoretical foundation for the further application of Zanthoxylum bungeanum.