Abstract: Chinese medicinal herb Thymus mongolicus Ronn has been used as an antiinflammatory and antigastro disease drug in China, so the analysis of its components is valuable. We extracted its chemical constituents by supercritical Carbon dioxide(SFE-CO2) and steam distillation(SD). The extracts of SFE-CO2 and SD were analyzed and established by means of capillary GC/MS on HP-5(6890/5973) instrument. 75 compounds of SFE-CO2 and 55 compounds of SD were identified.Comparing the different results of the two ways, we think that the method of SFE-CO2 is superior to the method of SD in extracting and analyzing the Chinese medicinal herb.