The pharmacodynamics and its circulatory effects of alcuronium and atracurium were investigated in cardiac and noncardiac surgical patients.The results demonstrated that:l Compared with atracurium group,the duration of action of alcuronium is longer in cardiac patients than that of non-cardiac patients, but there is no difference in the onset of action between these two groups; 2. Half of the patients which received alcuronium need reversal with neostigminel 3. The effects on the circulation of these two drugs were nor remarkable;Therefore,alcuronium is also suitable for cardiac and non-cardiac surgical patients