Abstract: The "Compound Mixture of Two Fairies" (Ⅰ) has been used as a hypotensive drug. One of its chief ingredients is Phellodendron chinense (Ⅱ). Berberis spp. (Ⅲ)contains also much berbcrine. Hence Ⅱhas been substituted by Ⅲ in making the Compound Mixture Ⅳ. In this paper Ⅱand Ⅲ were studied in the form of fluidextracts. The dosages used were expressed in terms of crude drugs. The intraperitoneal LD₅₀ in mice were 2.7 g/kg for Ⅱ and 3.1 g/kg for Ⅲ. Intraperitoneal injections in anesthetized cats produced, in 90 minutes, an average “% of hypotensive areas”of -30%for Ⅰ(4g/kg),—30% forⅡ(2g/kg),—42% for Ⅲ(2g/kg), and —32% for Ⅳ(4g/kg). Six renal hypertensive dogs were fed Ⅳ 15—30 g/kg/day for 20 days. There were no remarkable changes in blood pressure, EKG, BSP retention, and blood NPN. Three normal dogs were fed daily Ⅳ 45 g/kg for 3 weeks. Abnormal alteration was not found in EKG, liver and kidney function tests, nor was toxic sign noticed in the microscopic examinations. Sixteen water-soluble portions from different fractions of Ⅲ were screened over by single intravenous injections in anesthetized cats, 2—3 cats for each portion. Six of them yielded an average“%of hypotensive areas” exceeding —30%. Since Ⅲ is abundant in China and low in toxicity, it seems to be a promising source of hypotensive drugs.