General pharmacological properties of ADP, a new pharmaceutical composition, which contains a mixed water extract obtained from the mixture of Phellodendron cortex (Phellodendron amurense) and Anemarrhena rhizoma (Anemarrhena asphodeloides), as the active ingredients, were investigated in experimental animals administering orally and in vitro test system. ADP had no influences on general behavior, pentobarbital sleeping time, spontaneous motor activity, motor coordination of mice, normal body temperature, chemoshock produced by pentylenetetrazole and writhing syndromes induced by 0.8% acetic acid at the dose of 150 and 1500 mg/kg. Gastric secretion of rats and intestinal motility of mice were not also influenced by the administration of ADP at doses of 150 and 1500 mg/kg, with the exception of the significant decrease of free HCI concentration at a dose of 1500 mg/kg in rats. ADP (150 and 1500 mg/kg) did not alter mean arterial blood pressure and heart rate in conscious rats. ADP given to anesthetized rats showed no effect on respiratory rate at the same doses. In in vitro experiments, ADP at the concentration of 150 mg/L did not show direct effect and inhibitory or augmentative action on histamine- or acetylcholine-induced contractions in the isolated ileum of guinea-pig. Taken together, these results indicate that ADP does not induce any adverse effects in experimental animals.