Abstract: A crude cardiac glucoside preparation (total glucosides) was obtained from Adonis brevistyla Franch by Mr. Chou Gyn (周俊). The authors report on the cardiotonic action of the substance as follows: 1. By experiments on frog's and rabbit's hearts in situ, as well as on isolated guinea-pig's heart, the drug was found to be cardiotonic. 2. The changes of EKG in rabbits by intravenous injections of the drug were similar to those induced by other cardiac glucosides. 3. When assayed according to the method adopted for digitalis in the Chinese Pharmacopeia, the MLD of the drug in pigeons was 7.08 ± 0.15 (S.D.) mg/kg.