OBJECTIVE： To investigate the effects of different elutions of Hyssopus cuspidatus on smooth muscle contraction of isolated tracheal in Guinea pigs. METHODS： Isolated tracheal rings were prepared and soaked in Krebs-Henseleit， using acetylcholine （ACh， 1×10－7 g/mL） or histamine （His， 1×10－6 g/mL） to induce contraction of tracheal rings， then the effects of H. cuspidatus water elution and 30％， 50％， 60％， 70％， 95％ ethanol elutions with mass concentrations of 0.08， 0.16， 0.32， 0.64， 1.28， 2.56 mg/mL on contraction of tracheal rings were respectively investigated. Contraction curves were recorded and antispasmodic rates were calculated. Tests were treated with saline as blank control and aminophylline （0.08 mg/mL） as positive control. RESULTS： Compared with blank control， 0.16-2.56 mg/mL 30％， 50％ ethanol elution， 0.32-2.56 mg/mL 60％ ethanol elution and 0.64-2.56 mg/mL 70％， 95％ ethanol elution can obviously inhibit ACh-induced contraction of tracheal rings， antispasmodic rates were obviously increased （P＜0.05 or P＜0.01）； 0.32-2.56 mg/mL water elution and 30％， 50％ ethanol elution， 0.16-2.56 mg/mL 60％， 70％ ethanol elution and 1.28-2.56 mg/mL 95％ ethanol elution can obviously inhibit His-induced contraction of tracheal rings， antispasmodic rates were obviously increased （P＜0.05 or P＜0.01）. The effects of 2.56 mg/mL 60％ ethanol elution approach to aminophylline. CONCLUSIONS： Different elutions of H. cuspidatus has certain antagonistic effect on the ACh-induced or His-induced smooth muscle contraction of isolated tracheal in Guinea pigs； 60％ ethanol elution shows the strongest effect， which has similar effects with aminophylline at high mass concentration.