Through the method of literature research

the study on the original dose of classical prescriptions by Japanese Kampo doctors of all ages were traced. The study on the original dose of classical prescriptions by Kampo medicine can be divided into four stages of "imitation

digestion

original creation

review"

that is

the imitation stage of introducing Chinese medicine directly by sending Sui and Tang envoys

including the Asuka

Nara

Heian

and Kamakura eras; the digestion stage of each school advocating different perspectives with the rise of the later generation school

the ancient prescription school and other schools

including the Muromachi

Sengoku

Azuchi Momoyama period

and the early and middle periods of the Edo ear; after seclusion

the textual research school rose. It is the stage of original creation when many perspectives that different from Chinese medical filed were proposed

including the late Edo period and the Meiji Restoration period; the review stage of reanalyzing the original dose of classical prescription through scientific methods such as drug weight measurement and laboratory research in modern times. The result of modern Japanese research is that 1 liang in classical prescription is equal to 14 g. This research result is most consistent with history and reality

and is basically consistent with the result of "1 liang is about 13.8 g" in China.