Abstract: Compositus Guan-Xin NO 2 has been Used for the treatment of angina pectoris with favorable results. In this paper studies on the effect of the compositus on myocardial ischaemia and hypoxia are. described. The compositus composed of traditional Chinese Huo Xue Hua Yu (medicines for the treatment of blood stasis and for the improvement of circulation) drugs Dan-Shen (Salvia miltiorrhiza)、Chuan-Xiong (Ligusticum Wallichii), Hong-Hua (Carthamus tinctorius), Chi-Shao (Paeonia lactiflora)and Jiang-Xiang (Dalbergia odorifera). The aqueous or alcoholic extract of the compositus. and the decoctions of the ingredients of the compositus were used.Experimental myocardial ischaemia was induced by intravenous injection of pituitrin in intact unanesthetized rats. The pituitrin induced acute ischaemia was reduced by the compositus pretreatment as indicated by improvement of ECG. Chuan-Xiong、Hong-Hua or Chi-Shao showed a prophylactic action on the myocardial ischaemia. The hypoxic ECG was not affected by injection of Dan-Shen or Jiang-Xiang.Mice were subjected to low pressure hypoxia or hypoxia induced by inhalation of 6 per cent oxygen in nitrogen. The survival rate or survival time was estimated. The compositus, given intravenously or orally, increased the resistance of mice to hypoxia. A similar result was obtained in mice pretreated with isoproterenol. All the ingredients of the compositus, except Hong-Hua, were shown to increase the resistance of mice to hypoxia in different degrees when administered orally.