The raw material of berberine hydrochloride was examined for preparation of the "Berberine Hydrochloride Reference Standard". The candidate material was evaluated physico-chemically by a collaborative study in which five laboratories participated. Analytical data obtained were as follows: UV spectrum, lambda max = 228, 263, 345, and 421 nm and specific absorbance E1%1cm at each lambda max = 814, 794, 722, and 160, respectively; IR spectrum, specific absorption wave numbers at 2845, 1633, 1568, and 1506 cm-1; thin-layer chromatography, some laboratories detected a trace amount of one or two spot and others not detected; high-performance liquid chromatography, 2-5 impurities were detected and the amount of any impurities were estimated to be less than 0.05% and the total amount less than 0.2%. Based on the above results, the candidate material was authorized as the Berberine Hydorochloride Reference Standard of National Institute of Health Sciences.