Abstract:In the research of Allium macrostemon Bunge volatile oil antibacterial activity test， Penicillium and Saccharomyces cerevisiae， Escherichia coli， Staphylococcus aureus were selected，four kinds of common mold， fungi， bacteria as test strain， and the filter paper method was used to analysis of antibacterial activity. Results showed that Allium macrostemon Bunge volatile oil had obvious inhibitory effect on the four kinds of strain. Ac－ cording to the diameter size of the inhibition zone， it could be judged that the inhibitory effect on Escherichia coli and Staphylococcus aureus were relatively stronger； while on the effect Penicillium and Saccharomyces cerevisiae were modest. Taking colorimetric determination to different concentrations of antibacterial liquid cul－ ture medium with spectrophotometer determined the OD value， the lower value， the better antibacterial activity. The results showed that the minimum inhibitory concentration of Allium macrostemon Bunge volatile oil antibac－ terial liquid on Saccharomyces cerevisiae was 1.25 %， on Penicillium was 0.63 %， on Escherichia coli was 0.63 % and on Staphylococcus aureus was 0.31 %.