Abstract: Divasid, a cardiac glucosidal preparation obtained from the fruits of Yang-chiao-ou Stropanthus divaricatus (Lour) Hook et Arn., has been used as a substitute for kstrophanthin in the treatment of heart failure. The authors' study was to determine whether the methods for estimating the potency of digitalis preparations described in the Pharmacopeia of People's Republic of China could be applied to the assay of divasid. It was observed that in several, batches of samples the ratio of the M.L.D. of divasid in pigeons to that in cats was almost constant, which was analogous to the ratio obtained with g-strophanthin. Experiments in pigeons gave a coefficient of variation of 9.75% and those in cats 14.56%. Hence, a non-anesthetized pigeon method for bioassay of divasid with strophanthin G as standard was proposed. According to the method proposed the potencies of 18 batches of divasid (both the powder and the injection) were estimated. The fiducial limits of error (P=0.95) of the estimated potencies were around 10%.