Essential oil from the flowers of Michelia figo was extracted by steam distillation and the antimicrobial activities of the essential oil on bacteria and fungi were tested by plate counts and filter paper methods. Then the chemical constituents of the essential oil were analyzed by GC/MS. The results showed that: the antimicrobial effect of the essential oil from the flowers of M. figo on Bacillus sabtills, Escherichia coli and Mucor racemosus were good and their inhibitory rates were up to 70.36%, 60.24% and 65.52%. There were certain antimicrobial effect of the essential oil on Staphylococcus aureus and Aspergillus flavus, but no antimicrobial effect on Rhizopus oryzae. Thirty compounds were separated and identified from the essential oil including 14 aliphatic compounds and 16 terpenoid compounds.