By analysing the regional charactertics of distribution of producing locations of medicines included in Shennong's Classic of Meteria Medica, it is pointed out that, based on quantity of production, Yizhou of the 13 bu - administrative regions and Taishan Prefecture are the locations for massive production of medicines in the Han dynasty. Judging from distribution of locations, Luoyang, the Eastern Capital and Chang'an the Western Capital are the two centers, with the former more productive than the latter. It is suggested that the Hongnong Prefecture, the mid point between Luoyang and Chang'an, was an important crude drug trading center in the Eastern Han dynasty. The records of producing locations in Shennong's Classic of Meteria Medica reflects the importance it attaches to the genuine producing sites and demonstrates the changes of genecine locations of drug production since the Qin - Han periods.