Background: Kuan xiong aerosol (KXA) is a kind of Chinese herbal compound used to regulating qi-flowing for relieving pain and improving angina. However, little pharmacological study of this traditional Chinese medicine preparation has been reported to confirm these activities. Objective: This article aims to observe the effect of resisting acute myocardial ischemia (AMI) in vivo and dilating vessel in vitro of KXA. Materials: The AMI model involves intravenously injecting pituitary (2 U.kg-1) into the ear of rabbits. Electrocardiograph (ECG) T waves were then recorded after administration and the falling range was calculated. Following this, the level of serum Cardiac troponin T (cTn-T) and the histopathology of the cardiac muscle tissue was evaluated. In vitro, the effect of KXA on vasodilation of isolated aortic rings that had been pre-contracted with KCl (30 mM) was observed. Results: It was found KXA reduced ECG ST-T waves and serum cTn-T in the rabbit AMI model, protected myocardial tissue from fracturing and loss of myocardial fibers, and inhibited inflammatory cell infiltration, cavitation degeneration and karyopyknosis of the myocardial matrix. Furthermore, the administration of 0.215, 1.075 and 2.150 mg.mL-1 KXA resulted in significant relaxation of the aortic rings at a rate of 69.63 %, 90.14 % and 118.72 % (p < 0.01) of the untreated ones, and a second shrinkage ratio of 20.17 %, 4.29 %, and 4.54 % (p < 0.01) of the untreated ones, respectively. Conclusions: these results suggest KXA protects against AMI, contributes to dilation of blood vessels and has long-acting effectiveness.