Objective: To study the chemical constituents and bioactivity of essential oil from Dasymaschalon rostratum. Method: The essential oil was extracted by hydrodistillation and separated by capillary GC. The chemical constituents were determined by normalization and were identified by MS. Result: Ninty-one chromatographic peaks were detected and seventy-three compounds were identified

which was 90.25% of the total essential oil. The essential oil from D. rostratum showed inhibitory activity against Staphyloccocus aureus Rosenbach

Escherichia coli

Bacillus subtilis

exhibited higher activity to restrain Leukemia cells (K-562) and Liver cancer cells(BEL-7402)

with IC50 values of 10.47

47.2 mg·L-1 respectively. Conclusion: It is first time to extract volatile oil from Dasymaschalon and identify the compunds

most of which were alkene compunds. Many active ingredients were contained in the essential oil from D. rostratum

the experiment basis were provided for the further research of D. rostratum.