The extract of ginger the rhizomes of Zingiber officinale Roscoe (Zingiberaceae) has been reported to possess anti-hyperactivity and anti-inflammation on airway the present study described brochodilatory activity of ginger oil were analyzed by gas chromatography and mass spectrometer Citral eucalyptol and camphene were found to be the major components Ginger oil and citral but not camphene suppressed rat tracheal contraction induced by carbachol (CCh) consistent with previous report eucalyptol showed a relaxing effect on rat airway since the content of eucalyptol in ginger oil was relatively low the contribution of eucalyptol to the bronchodilatory effect of ginger oil was small to elucidate the mechanisms responsible for the myorelaxing effect propranolol (a β-adrenergic receptor antagonist) indomethacin (a COX inhibitor) and L-NAME (a NOS inhibitor) were used to block the inhibitory effects of ginger oil and citral it was found that propra nolol but not indomethacin and L-NAME reversed bronchodilatory effects of both ginger oil and citral suggesting that a possible mechanism involved β-adrenergic receptor this study provides the pharmacological basis supporting the therapeutic potential of Z officinale rhizomes as a bronchodilator