Abstract: A tincture was prepared from the roots of Tupistra aurantiaca Wall (Fam. Liliaceae), that grew wild in the west part of Yunnan Province in China; after alcohol was removed by vaporization, it was dissolved in distilled water at a suitable concen- tration, and then used in experiments. In the course of all experiments, the authors used Tinctura Digitalis as control. The action of the drug was demonstrated to be as follows: 1. After removal of alcohol from Tinctura of Tupistra aurantiaca, the residue gave positive reactions with Legal and Keller-Kiliani tests. 2. By experiments on frogs' and rabbits' hearts in situ, isolated guinea pigs' hearts, and EKG on cats, there is evidence that the characteristics of cardiotonic action of the drug and those of Digitalis are alike. 3. By experiments on rabbits' hearts in situ and isolated guinea pigs' hearts, it was found that the phases of action, for instance, time of onset of cardiotonic action, maxi- mal effect, regression, and disappearance, of these two drugs were similar. 4. The pigeon units of the roots of Tupistra aurantiaca and the leaves of Digitalis according to the Chinese Pharmacopeia was found to be 207.14±13.07mg/kg and 101.42±5.19mg/kg (S.D.) respectively.