Abstract
In Kampo medicine, a decoction is prepared by boiling small pieces of the ingredients enough for one day's dosage. The prepared liquid is separated into two or three parts for each dose. The Hejijufang adopted the Zhusanfa, which is the method of preparing the decoction using powdered ingredients of prescriptions rather than pieces. In the Zhusanfa, the dosage is determined from the premixture of the powdered ingredients. In the Zhusanfa, although the whole quantities of prescriptions are written with the ancient weight unit, the notation of the dosage is indicated by the current weight unit, Qian. The dosage was regulated for weights and measures in the Song dynasty. In contrast, preparation methods using small pieces and powder were both adopted in Li Dongyuan's medical books. In Li Dongyuan's treatments, decoctions using small pieces were administrated for acute diseases expected to respond to changes in dosage. Decoctions using powder（the Zhusanfa) were adapted to long-term administration.
