Abstract: This paper reports the flash distillation-capillary gas chromatography-massspectrometry for analyzing the volatile components in several kinds of Chineseherbal medicines Curcuma longal., A. Lancea (Thunb.) DC., Foeniculumualgare Mill. and Cinnamomun cassia presl. Compared with usual methods,this way is easier, faster, and a few of sample is needed. The results bothflash distillation and steam distillation are similar. In Addition, the flashdistillation analysis conditions (flash distillation temperature and time) arealso studied.