Essential oil of subterranean part of Cacalia tangutica（Maxim.） Hand.-Mazz was analyzed by GC-MS in two different capillary columns of different polarities.The results showed that thirty-one components were identified in the oil

and main compounds of the oil were α-Zingiberene（13.49%）

Germacrene D（10.76%）

α-Pinene（8.54%）

Caryophyllene（Z-）（6.36%）

Linalool（6.16%）

β-Myrcene（4.89%）

β-Ocimene（Z-）（4.40%）and Ocimenone（Z-）（3.58%）.The antimicrobial activity of the oil was evaluated against 2 fungi and 12 bacteria including 6 clinical isolated strains using the agar disc diffusion and broth micro dilution methods.Our results showed that the oil presented a broad antimicrobial spectrum

and had better antimicrobial activity against yeast and gram-positive bacteria

the MIC values were 0.16-5.00 g/L and the MBC values was 0.16-5.00 g/L.