The essential oil content in the roots of Chrysopogon aucheri growing wild in south of Iran was found to be 0.1% based on the fresh weight. The oil was analyzed by Gas Chromatography (GC) and Gas Chromatography-Mass Spectrometry (GC/MS). Twenty constituents were identified, which approximately constituted 97.3% of the root oil. Monoterpenes consist more than 88% of the oil of which the major components were characterized as α-pinene (23.1%), (E)-β-ocimene (20.9%), (Z)-β-Ocimene (12.0%) and α-phellandrene (10.8%).