Abstract: A study on the pharmacological action of Adonis amurensis Regel et Radd, which grows wild in North-cast China, is reported. Experiments with isolated hearts of frogs and rabbits and the heart cavity of dogs (in situ) all show that, like digitalis, Adonis amurensis has a cardiotonic action. In the heart-lung preparation, the heart showed a slight failure after the addition of chloral hydrate, but infusion of infusum Adonis amurensis into the heart decreased the elavated venous pressure and increased the decreased output per minute of the heart, thus relieving the heart failure. ECG also showed the digitalis like action on the heart, i. e., prolonging of the P-Q interval, shortening of the R-T interval, declining the S-T segment, and a typical T-wave change. Determination of the minimum lethal dose of Adonis amurensis showed that its minimum lethal dose is smaller than that of Adonis vernalis, but greater than that of digitalis. The drug has only a little cumulative action. Hypodermic injection and infusum into the stomach of rabbits and dogs with various doses demonstrated that Adonis amurensis possess sedative and emetic action. The cat venous emetic dose is 24—36 mg/kg and the therapeutic dose calculated by the minimum lethal dose is far smaller than its emetic dose. Hence the clinical application of Adonis amurensis may be safe.