Chemical and physical characteristics of commercial Faek-hom roots were reported. The morphological characters, chemical identification, ash content, moisture content, extractives content and volatile oil content were carried out. It was found that commercial crude drug was not derived from the root of Vetiveria zizanioides Nash (Family Gramineae) or Faek-hom, but it was derived from the root of Ophiopogon intermedius Don. (Family Liliaceae) or Yaa-phraek-hin. Both kinds of root had quite different morphological characters. Authentic Faek-hom root is yellowish brown or whitish yellow in color with weak odor and after broken will be separated from each other while the commercial one is reddish brown in color with strong odor and after broken the whitish pith remains unseparately. Thin-layer and gas chromatographic analysis showed that the essential oil from commercial Faek-hom roots were different from standard vetiver oil obtained from the roots of Vetiveria zizanioides Nash. Besides, the average percentage of essential oil content, water extractive and ethanol extractive of commercial Faek-hom were 1.56, 50.82 and 8.23 respectively, while the authentic ones were 0.29, 2.53 and 3.13 respectively. The results of this study showed that the commercial crude drug was entirely supply of Yaa-phraek-hin root as Faek-hom root.

KEY WORDS : Faek-hom, Vetiveria zizanioides Nash, vetiver oil, quality specification.