Since the ancient system of weights and measures varied from one historical period to another, multiple units of measurement can be seen when reading ancient medical books. Modern printed medical books still record the original dosage of ancient prescriptions, mainly as a reference for understanding the meaning of the ancient formulae, structural characteristics, reasons for changes, and the proportion of drugs used in the clinical evidence. In clinical application, the dosage should be decided according to modern Chinese medicine and reference to recent medical cases, and according to the needs of region, age, physique, climate and disease. Wei Lanxiang, Department of Endocrinology, Xiyuan Hospital, Chinese Academy of Traditional Chinese Medicine According to the instructions of the State Council of China, from January 1, 1979, the metric system with “g” (gram) as the unit of measurement was adopted for all prescriptions of Chinese medicine nationwide. Hexadecimal and metric units of measurement conversion rate 1 catty (16 taels) = 0.5kg = 500g 1 city two = 31.25g 1 city money = 3.125g 1 city cent = 0.3125g 1 city cents = 0.03125g Comparison of measurement and scales through the ages Time period Ancient dosage of folded city system Ancient capacity folded city system Qin Dynasty a tael 0.5165 city two a liter 0.34 city liter Western Han Dynasty a tael 0.5165 taels, one liter, 0.34 liters, Xinmang, one tael, 0.4455 taels, one liter, 0.20 liters, Eastern Han, one tael, 0.4455 taels, one liter, 0.20 liters, Wei and Jin, one tael, 0.4455 taels, one liter, 0.21 liters, Northern Zhou, one tael, 0.5011 taels, one liter, 0.21 liters, Sui and Tang, one tael, 1.0075 taels, one liter, 0.58 liters, Song, one tael, 1.1936 taels, one liter, 0.66 liters. 0.66 shilings Ming Dynasty 1.1936 shilings 1 liter 1.07 shilings Qing Dynasty 1.194 shilings 1 liter (built) 1.0355 shilings